System Analysis and Design - Overview

Systems development is systematic process which includes phases such as planning,

analysis, design, deployment, and maintenance. Here, in this tutorial, we will primarily
focus on −

 Systems analysis

 Systems design

Systems Analysis
It is a process of collecting and interpreting facts, identifying the problems, and
decomposition of a system into its components.

System analysis is conducted for the purpose of studying a system or its parts in order
to identify its objectives. It is a problem solving technique that improves the system
and ensures that all the components of the system work efficiently to accomplish their
purpose.

Analysis specifies what the system should do.

Systems Design
It is a process of planning a new business system or replacing an existing system by
defining its components or modules to satisfy the specific requirements. Before
planning, you need to understand the old system thoroughly and determine how
computers can best be used in order to operate efficiently.

System Design focuses on how to accomplish the objective of the system.

System Analysis and Design (SAD) mainly focuses on −

 Systems

 Processes

 Technology

What is a System?
The word System is derived from Greek word Systema, which means an organized
relationship between any set of components to achieve some common cause or
objective.
A system is “an orderly grouping of interdependent components linked together
according to a plan to achieve a specific goal.”

Constraints of a System
A system must have three basic constraints −

 A system must have some structure and behaviorwhich is designed to achieve a predefined
objective.

 Interconnectivity and interdependence must exist among the system components.

 The objectives of the organization have a higher priority than the objectives of its
subsystems.

For example, traffic management system, payroll system, automatic library system,
human resources information system.

Properties of a System
A system has the following properties −

Organization
Organization implies structure and order. It is the arrangement of components that
helps to achieve predetermined objectives.

Interaction
It is defined by the manner in which the components operate with each other.

For example, in an organization, purchasing department must interact with production

department and payroll with personnel department.

Interdependence
Interdependence means how the components of a system depend on one another. For
proper functioning, the components are coordinated and linked together according to a
specified plan. The output of one subsystem is the required by other subsystem as
input.

Integration
Integration is concerned with how a system components are connected together. It
means that the parts of the system work together within the system even if each part
performs a unique function.

Central Objective
The objective of system must be central. It may be real or stated. It is not uncommon
for an organization to state an objective and operate to achieve another.
The users must know the main objective of a computer application early in the analysis
for a successful design and conversion.

Elements of a System
The following diagram shows the elements of a system −

Outputs and Inputs

 The main aim of a system is to produce an output which is useful for its user.

 Inputs are the information that enters into the system for processing.

 Output is the outcome of processing.

Processor(s)
 The processor is the element of a system that involves the actual transformation of input into
output.

 It is the operational component of a system. Processors may modify the input either totally or
partially, depending on the output specification.

 As the output specifications change, so does the processing. In some cases, input is also
modified to enable the processor for handling the transformation.

Control
 The control element guides the system.

 It is the decision–making subsystem that controls the pattern of activities governing input,
processing, and output.
  The behavior of a computer System is controlled by the Operating System and software. In
order to keep system in balance, what and how much input is needed is determined by
Output Specifications.

Feedback
 Feedback provides the control in a dynamic system.

 Positive feedback is routine in nature that encourages the performance of the system.

 Negative feedback is informational in nature that provides the controller with information for
action.

Environment
 The environment is the “supersystem” within which an organization operates.

 It is the source of external elements that strike on the system.

 It determines how a system must function. For example, vendors and competitors of
organization’s environment, may provide constraints that affect the actual performance of the
business.

Boundaries and Interface

 A system should be defined by its boundaries. Boundaries are the limits that identify its
components, processes, and interrelationship when it interfaces with another system.

 Each system has boundaries that determine its sphere of influence and control.

 The knowledge of the boundaries of a given system is crucial in determining the nature of its
interface with other systems for successful design.

Types of Systems
The systems can be divided into the following types −

Physical or Abstract Systems

 Physical systems are tangible entities. We can touch and feel them.

 Physical System may be static or dynamic in nature. For example, desks and chairs are the
physical parts of computer center which are static. A programmed computer is a dynamic
system in which programs, data, and applications can change according to the user's needs.

 Abstract systems are non-physical entities or conceptual that may be formulas, representation
or model of a real system.

Open or Closed Systems

  An open system must interact with its environment. It receives inputs from and delivers
outputs to the outside of the system. For example, an information system which must adapt
to the changing environmental conditions.

 A closed system does not interact with its environment. It is isolated from environmental
influences. A completely closed system is rare in reality.

Adaptive and Non Adaptive System

 Adaptive System responds to the change in the environment in a way to improve their
performance and to survive. For example, human beings, animals.

 Non Adaptive System is the system which does not respond to the environment. For example,
machines.

Permanent or Temporary System

 Permanent System persists for long time. For example, business policies.

 Temporary System is made for specified time and after that they are demolished. For
example, A DJ system is set up for a program and it is dissembled after the program.

Natural and Manufactured System

 Natural systems are created by the nature. For example, Solar system, seasonal system.

 Manufactured System is the man-made system. For example, Rockets, dams, trains.

Deterministic or Probabilistic System

 Deterministic system operates in a predictable manner and the interaction between system
components is known with certainty. For example, two molecules of hydrogen and one
molecule of oxygen makes water.

 Probabilistic System shows uncertain behavior. The exact output is not known. For example,
Weather forecasting, mail delivery.

Social, Human-Machine, Machine System

 Social System is made up of people. For example, social clubs, societies.

 In Human-Machine System, both human and machines are involved to perform a particular
task. For example, Computer programming.

 Machine System is where human interference is neglected. All the tasks are performed by the
machine. For example, an autonomous robot.

Man–Made Information Systems

 It is an interconnected set of information resources to manage data for particular
organization, under Direct Management Control (DMC).
  This system includes hardware, software, communication, data, and application for producing
information according to the need of an organization.

Man-made information systems are divided into three types −

 Formal Information System − It is based on the flow of information in the form of memos,
instructions, etc., from top level to lower levels of management.

 Informal Information System − This is employee based system which solves the day to
day work related problems.

 Computer Based System − This system is directly dependent on the computer for
managing business applications. For example, automatic library system, railway reservation
system, banking system, etc.

Systems Models
Schematic Models
 A schematic model is a 2-D chart that shows system elements and their linkages.

 Different arrows are used to show information flow, material flow, and information feedback.

Flow System Models

 A flow system model shows the orderly flow of the material, energy, and information that hold
the system together.

 Program Evaluation and Review Technique (PERT), for example, is used to abstract a real
world system in model form.

Static System Models

 They represent one pair of relationships such as activity–time or cost–quantity.

 The Gantt chart, for example, gives a static picture of an activity-time relationship.

Dynamic System Models

 Business organizations are dynamic systems. A dynamic model approximates the type of
organization or application that analysts deal with.

 It shows an ongoing, constantly changing status of the system. It consists of −

o Inputs that enter the system

o The processor through which transformation takes place

o The program(s) required for processing

o The output(s) that result from processing.

Categories of Information
There are three categories of information related to managerial levels and the decision
managers make.

Strategic Information
 This information is required by topmost management for long range planning policies for next
few years. For example, trends in revenues, financial investment, and human resources, and
population growth.

 This type of information is achieved with the aid of Decision Support System (DSS).

Managerial Information
 This type of Information is required by middle management for short and intermediate range
planning which is in terms of months. For example, sales analysis, cash flow projection, and
annual financial statements.

 It is achieved with the aid of Management Information Systems (MIS).

Operational information
 This type of information is required by low management for daily and short term planning to
enforce day-to-day operational activities. For example, keeping employee attendance
records, overdue purchase orders, and current stocks available.

 It is achieved with the aid of Data Processing Systems (DPS).

System Development Life Cycle

An effective System Development Life Cycle (SDLC) should result in a high quality
system that meets customer expectations, reaches completion within time and cost
evaluations, and works effectively and efficiently in the current and planned Information
Technology infrastructure.

System Development Life Cycle (SDLC) is a conceptual model which includes policies
and procedures for developing or altering systems throughout their life cycles.

SDLC is used by analysts to develop an information system. SDLC includes the following
activities −

 requirements

 design

 implementation

 testing

 deployment

 operations

 maintenance

Phases of SDLC
Systems Development Life Cycle is a systematic approach which explicitly breaks down
the work into phases that are required to implement either new or modified Information
System.
Feasibility Study or Planning
 Define the problem and scope of existing system.

 Overview the new system and determine its objectives.

 Confirm project feasibility and produce the project Schedule.

 During this phase, threats, constraints, integration and security of system are also
considered.

 A feasibility report for the entire project is created at the end of this phase.

Analysis and Specification

 Gather, analyze, and validate the information.

 Define the requirements and prototypes for new system.

 Evaluate the alternatives and prioritize the requirements.

 Examine the information needs of end-user and enhances the system goal.
  A Software Requirement Specification (SRS) document, which specifies the software,
hardware, functional, and network requirements of the system is prepared at the end of this
phase.

System Design
 Includes the design of application, network, databases, user interfaces, and system
interfaces.

 Transform the SRS document into logical structure, which contains detailed and complete set
of specifications that can be implemented in a programming language.

 Create a contingency, training, maintenance, and operation plan.

 Review the proposed design. Ensure that the final design must meet the requirements stated
in SRS document.

 Finally, prepare a design document which will be used during next phases.

Implementation
 Implement the design into source code through coding.

 Combine all the modules together into training environment that detects errors and defects.

 A test report which contains errors is prepared through test plan that includes test related
tasks such as test case generation, testing criteria, and resource allocation for testing.

 Integrate the information system into its environment and install the new system.

Maintenance/Support
 Include all the activities such as phone support or physical on-site support for users that is
required once the system is installing.

 Implement the changes that software might undergo over a period of time, or implement any
new requirements after the software is deployed at the customer location.

 It also includes handling the residual errors and resolve any issues that may exist in the
system even after the testing phase.

 Maintenance and support may be needed for a longer time for large systems and for a short
time for smaller systems.

Life Cycle of System Analysis and Design

The following diagram shows the complete life cycle of the system during analysis and
design phase.
Role of System Analyst
The system analyst is a person who is thoroughly aware of the system and guides the
system development project by giving proper directions. He is an expert having
technical and interpersonal skills to carry out development tasks required at each
phase.

He pursues to match the objectives of information system with the organization goal.

Main Roles
 Defining and understanding the requirement of user through various Fact finding techniques.

 Prioritizing the requirements by obtaining user consensus.

 Gathering the facts or information and acquires the opinions of users.

 Maintains analysis and evaluation to arrive at appropriate system which is more user friendly.

 Suggests many flexible alternative solutions, pick the best solution, and quantify cost and
benefits.

 Draw certain specifications which are easily understood by users and programmer in precise
and detailed form.

 Implemented the logical design of system which must be modular.

 Plan the periodicity for evaluation after it has been used for some time, and modify the
system as needed.

Attributes of a Systems Analyst

The following figure shows the attributes a systems analyst should possess −

Interpersonal Skills

 Interface with users and programmer.

 Facilitate groups and lead smaller teams.

 Managing expectations.

 Good understanding, communication, selling and teaching abilities.

 Motivator having the confidence to solve queries.

Analytical Skills

 System study and organizational knowledge

 Problem identification, problem analysis, and problem solving

 Sound commonsense
  Ability to access trade-off

 Curiosity to learn about new organization

Management Skills

 Understand users jargon and practices.

 Resource & project management.

 Change & risk management.

 Understand the management functions thoroughly.

Technical Skills

 Knowledge of computers and software.

 Keep abreast of modern development.

 Know of system design tools.

 Breadth knowledge about new technologies.

System Analysis & Design - System Planning

What is Requirements Determination?
A requirement is a vital feature of a new system which may include processing or
capturing of data, controlling the activities of business, producing information and
supporting the management.

Requirements determination involves studying the existing system and gathering details
to find out what are the requirements, how it works, and where improvements should
be made.

Major Activities in requirement Determination

Requirements Anticipation
 It predicts the characteristics of system based on previous experience which include certain
problems or features and requirements for a new system.

 It can lead to analysis of areas that would otherwise go unnoticed by inexperienced analyst.
But if shortcuts are taken and bias is introduced in conducting the investigation, then
requirement Anticipation can be half-baked.
Requirements Investigation
 It is studying the current system and documenting its features for further analysis.

 It is at the heart of system analysis where analyst documenting and describing system
features using fact-finding techniques, prototyping, and computer assisted tools.

Requirements Specifications
 It includes the analysis of data which determine the requirement specification, description of
features for new system, and specifying what information requirements will be provided.

 It includes analysis of factual data, identification of essential requirements, and selection of

Requirement-fulfillment strategies.

Information Gathering Techniques

The main aim of fact finding techniques is to determine the information requirements of
an organization used by analysts to prepare a precise SRS understood by user.

Ideal SRS Document should −

 be complete, Unambiguous, and Jargon-free.

 specify operational, tactical, and strategic information requirements.

 solve possible disputes between users and analyst.

 use graphical aids which simplify understanding and design.

There are various information gathering techniques −

Interviewing
Systems analyst collects information from individuals or groups by interviewing. The
analyst can be formal, legalistic, play politics, or be informal; as the success of an
interview depends on the skill of analyst as interviewer.

It can be done in two ways −

 Unstructured Interview − The system analyst conducts question-answer session to acquire

basic information of the system.

 Structured Interview − It has standard questions which user need to respond in either
close (objective) or open (descriptive) format.

Advantages of Interviewing

 This method is frequently the best source of gathering qualitative information.

  It is useful for them, who do not communicate effectively in writing or who may not have the
time to complete questionnaire.

 Information can easily be validated and cross checked immediately.

 It can handle the complex subjects.

 It is easy to discover key problem by seeking opinions.

 It bridges the gaps in the areas of misunderstandings and minimizes future problems.

Questionnaires
This method is used by analyst to gather information about various issues of system
from large number of persons.

There are two types of questionnaires −

 Open-ended Questionnaires − It consists of questions that can be easily and correctly

interpreted. They can explore a problem and lead to a specific direction of answer.

 Closed-ended Questionnaires − It consists of questions that are used when the systems
analyst effectively lists all possible responses, which are mutually exclusive.

Advantages of questionnaires

 It is very effective in surveying interests, attitudes, feelings, and beliefs of users which are
not co-located.

 It is useful in situation to know what proportion of a given group approves or disapproves of a

particular feature of the proposed system.

 It is useful to determine the overall opinion before giving any specific direction to the system
project.

 It is more reliable and provides high confidentiality of honest responses.

 It is appropriate for electing factual information and for statistical data collection which can be
emailed and sent by post.

Review of Records, Procedures, and Forms

Review of existing records, procedures, and forms helps to seek insight into a system
which describes the current system capabilities, its operations, or activities.

Advantages

 It helps user to gain some knowledge about the organization or operations by themselves
before they impose upon others.

 It helps in documenting current operations within short span of time as the procedure
manuals and forms describe the format and functions of present system.
  It can provide a clear understanding about the transactions that are handled in the
organization, identifying input for processing, and evaluating performance.

 It can help an analyst to understand the system in terms of the operations that must be
supported.

 It describes the problem, its affected parts, and the proposed solution.

Observation
This is a method of gathering information by noticing and observing the people, events,
and objects. The analyst visits the organization to observe the working of current
system and understands the requirements of the system.

Advantages

 It is a direct method for gleaning information.

 It is useful in situation where authenticity of data collected is in question or when complexity

of certain aspects of system prevents clear explanation by end-users.

 It produces more accurate and reliable data.

 It produces all the aspect of documentation that are incomplete and outdated.

Joint Application Development (JAD)

It is a new technique developed by IBM which brings owners, users, analysts,
designers, and builders to define and design the system using organized and intensive
workshops. JAD trained analyst act as facilitator for workshop who has some specialized
skills.

Advantages of JAD

 It saves time and cost by replacing months of traditional interviews and follow-up meetings.

 It is useful in organizational culture which supports joint problem solving.

 Fosters formal relationships among multiple levels of employees.

 It can lead to development of design creatively.

 It Allows rapid development and improves ownership of information system.

Secondary Research or Background Reading

This method is widely used for information gathering by accessing the gleaned
information. It includes any previously gathered information used by the marketer from
any internal or external source.

Advantages

 It is more openly accessed with the availability of internet.

  It provides valuable information with low cost and time.

 It act as forerunner to primary research and aligns the focus of primary research.

 It is used by the researcher to conclude if the research is worth it as it is available with

procedures used and issues in collecting them.

Feasibility Study
Feasibility Study can be considered as preliminary investigation that helps the
management to take decision about whether study of system should be feasible for
development or not.

 It identifies the possibility of improving an existing system, developing a new system, and
produce refined estimates for further development of system.

 It is used to obtain the outline of the problem and decide whether feasible or appropriate
solution exists or not.

 The main objective of a feasibility study is to acquire problem scope instead of solving the
problem.

 The output of a feasibility study is a formal system proposal act as decision document which
includes the complete nature and scope of the proposed system.

Steps Involved in Feasibility Analysis

The following steps are to be followed while performing feasibility analysis −

 Form a project team and appoint a project leader.

 Develop system flowcharts.

 Identify the deficiencies of current system and set goals.

 Enumerate the alternative solution or potential candidate system to meet goals.

 Determine the feasibility of each alternative such as technical feasibility, operational

feasibility, etc.

 Weight the performance and cost effectiveness of each candidate system.

 Rank the other alternatives and select the best candidate system.

 Prepare a system proposal of final project directive to management for approval.

Types of Feasibilities
Economic Feasibility
 It is evaluating the effectiveness of candidate system by using cost/benefit analysis method.

 It demonstrates the net benefit from the candidate system in terms of benefits and costs to
the organization.

 The main aim of Economic Feasibility Analysis (EFS) is to estimate the economic requirements
of candidate system before investments funds are committed to proposal.

 It prefers the alternative which will maximize the net worth of organization by earliest and
highest return of funds along with lowest level of risk involved in developing the candidate
system.

Technical Feasibility
 It investigates the technical feasibility of each implementation alternative.

 It analyzes and determines whether the solution can be supported by existing technology or
not.

 The analyst determines whether current technical resources be upgraded or added it that
fulfill the new requirements.

 It ensures that the candidate system provides appropriate responses to what extent it can
support the technical enhancement.

Operational Feasibility
 It determines whether the system is operating effectively once it is developed and
implemented.

 It ensures that the management should support the proposed system and its working feasible
in the current organizational environment.

 It analyzes whether the users will be affected and they accept the modified or new business
methods that affect the possible system benefits.
  It also ensures that the computer resources and network architecture of candidate system are
workable.

Behavioral Feasibility
 It evaluates and estimates the user attitude or behavior towards the development of new
system.

 It helps in determining if the system requires special effort to educate, retrain, transfer, and
changes in employee’s job status on new ways of conducting business.

Schedule Feasibility
 It ensures that the project should be completed within given time constraint or schedule.

 It also verifies and validates whether the deadlines of project are reasonable or not.

Analysts use various tools to understand and describe the information system. One of
the ways is using structured analysis.

What is Structured Analysis?

Structured Analysis is a development method that allows the analyst to understand the
system and its activities in a logical way.

It is a systematic approach, which uses graphical tools that analyze and refine the
objectives of an existing system and develop a new system specification which can be
easily understandable by user.

It has following attributes −

 It is graphic which specifies the presentation of application.

 It divides the processes so that it gives a clear picture of system flow.

 It is logical rather than physical i.e., the elements of system do not depend on vendor or
hardware.

 It is an approach that works from high-level overviews to lower-level details.

Structured Analysis Tools

During Structured Analysis, various tools and techniques are used for system
development. They are −

 Data Flow Diagrams

 Data Dictionary

 Decision Trees
  Decision Tables

 Structured English

 Pseudocode

Data Flow Diagrams (DFD) or Bubble Chart

It is a technique developed by Larry Constantine to express the requirements of system
in a graphical form.

 It shows the flow of data between various functions of system and specifies how the current
system is implemented.

 It is an initial stage of design phase that functionally divides the requirement specifications
down to the lowest level of detail.

 Its graphical nature makes it a good communication tool between user and analyst or analyst
and system designer.

 It gives an overview of what data a system processes, what transformations are performed,
what data are stored, what results are produced and where they flow.

Basic Elements of DFD

DFD is easy to understand and quite effective when the required design is not clear and
the user wants a notational language for communication. However, it requires a large
number of iterations for obtaining the most accurate and complete solution.

The following table shows the symbols used in designing a DFD and their significance −
Symbol Name Symbol Meaning

Square Source or Destination of Data

Arrow Data flow

Circle Process transforming data

flow

Open Data Store

Rectangle

Types of DFD
DFDs are of two types: Physical DFD and Logical DFD. The following table lists the
points that differentiate a physical DFD from a logical DFD.

Physical DFD Logical DFD

It is implementation dependent. It is implementation independent.

It shows which functions are It focuses only on the flow of
performed. data between processes.

It provides low level details of It explains events of systems and

hardware, software, files, and data required by each event.
people.

It depicts how the current It shows how business operates;

system operates and how a not how the system can be
system will be implemented. implemented.

Context Diagram
A context diagram helps in understanding the entire system by one DFD which gives
the overview of a system. It starts with mentioning major processes with little details
and then goes onto giving more details of the processes with the top-down approach.

The context diagram of mess management is shown below.

Data Dictionary
A data dictionary is a structured repository of data elements in the system. It stores the
descriptions of all DFD data elements that is, details and definitions of data flows, data
stores, data stored in data stores, and the processes.

A data dictionary improves the communication between the analyst and the user. It
plays an important role in building a database. Most DBMSs have a data dictionary as a
standard feature. For example, refer the following table −

Sr.No. Data Name Description No. of Characters

1 ISBN ISBN Number 10

2 TITLE title 60

3 SUB Book Subjects 80

4 ANAME Author Name 15

Decision Trees
Decision trees are a method for defining complex relationships by describing decisions
and avoiding the problems in communication. A decision tree is a diagram that shows
alternative actions and conditions within horizontal tree framework. Thus, it depicts
which conditions to consider first, second, and so on.
Decision trees depict the relationship of each condition and their permissible actions. A
square node indicates an action and a circle indicates a condition. It forces analysts to
consider the sequence of decisions and identifies the actual decision that must be
made.

The major limitation of a decision tree is that it lacks information in its format to
describe what other combinations of conditions you can take for testing. It is a single
representation of the relationships between conditions and actions.

For example, refer the following decision tree −

Decision Tables
Decision tables are a method of describing the complex logical relationship in a precise
manner which is easily understandable.

 It is useful in situations where the resulting actions depend on the occurrence of one or
several combinations of independent conditions.

 It is a matrix containing row or columns for defining a problem and the actions.

Components of a Decision Table

  Condition Stub − It is in the upper left quadrant which lists all the condition to be checked.

 Action Stub − It is in the lower left quadrant which outlines all the action to be carried out to
meet such condition.

 Condition Entry − It is in upper right quadrant which provides answers to questions asked in
condition stub quadrant.

 Action Entry − It is in lower right quadrant which indicates the appropriate action resulting
from the answers to the conditions in the condition entry quadrant.

The entries in decision table are given by Decision Rules which define the relationships
between combinations of conditions and courses of action. In rules section,

 Y shows the existence of a condition.

 N represents the condition, which is not satisfied.

 A blank - against action states it is to be ignored.

 X (or a check mark will do) against action states it is to be carried out.

For example, refer the following table −

CONDITIONS Rule Rule Rule Rule

1 2 3 4

Advance payment made Y N N N

Purchase amount = Rs - Y Y N
10,000/-

Regular Customer - Y N -

ACTIONS

Give 5% discount X X - -

Give no discount - - X X

Structured English
Structure English is derived from structured programming language which gives more
understandable and precise description of process. It is based on procedural logic that
uses construction and imperative sentences designed to perform operation for action.

 It is best used when sequences and loops in a program must be considered and the problem
needs sequences of actions with decisions.

 It does not have strict syntax rule. It expresses all logic in terms of sequential decision
structures and iterations.

For example, see the following sequence of actions −

if customer pays advance

then

Give 5% Discount

else

if purchase amount >=10,000

then

if the customer is a regular customer

then Give 5% Discount

else No Discount

end if

else No Discount

end if

end if

Pseudocode
A pseudocode does not conform to any programming language and expresses logic in
plain English.

 It may specify the physical programming logic without actual coding during and after the
physical design.

 It is used in conjunction with structured programming.

 It replaces the flowcharts of a program.

Guidelines for Selecting Appropriate Tools

Use the following guidelines for selecting the most appropriate tool that would suit your
requirements −
  Use DFD at high or low level analysis for providing good system documentations.

 Use data dictionary to simplify the structure for meeting the data requirement of the system.

 Use structured English if there are many loops and actions are complex.

 Use decision tables when there are a large number of conditions to check and logic is
complex.

 Use decision trees when sequencing of conditions is important and if there are few conditions
to be tested.

System design is the phase that bridges the gap between problem domain and the
existing system in a manageable way. This phase focuses on the solution domain,
i.e. “how to implement?”

It is the phase where the SRS document is converted into a format that can be
implemented and decides how the system will operate.

In this phase, the complex activity of system development is divided into several
smaller sub-activities, which coordinate with each other to achieve the main objective
of system development.

Inputs to System Design

System design takes the following inputs −

 Statement of work

 Requirement determination plan

  Current situation analysis

 Proposed system requirements including a conceptual data model, modified DFDs, and
Metadata (data about data).

Outputs for System Design

System design gives the following outputs −

 Infrastructure and organizational changes for the proposed system.

 A data schema, often a relational schema.

 Metadata to define the tables/files and columns/data-items.

 A function hierarchy diagram or web page map that graphically describes the program
structure.

 Actual or pseudocode for each module in the program.

 A prototype for the proposed system.

Types of System Design

Logical Design
Logical design pertains to an abstract representation of the data flow, inputs, and
outputs of the system. It describes the inputs (sources), outputs (destinations),
databases (data stores), procedures (data flows) all in a format that meets the user
requirements.

While preparing the logical design of a system, the system analyst specifies the user
needs at level of detail that virtually determines the information flow into and out of the
system and the required data sources. Data flow diagram, E-R diagram modeling are
used.

Physical Design
Physical design relates to the actual input and output processes of the system. It
focuses on how data is entered into a system, verified, processed, and displayed as
output.

It produces the working system by defining the design specification that specifies
exactly what the candidate system does. It is concerned with user interface design,
process design, and data design.

It consists of the following steps −

 Specifying the input/output media, designing the database, and specifying backup
procedures.
  Planning system implementation.

 Devising a test and implementation plan, and specifying any new hardware and software.

 Updating costs, benefits, conversion dates, and system constraints.

Architectural Design
It is also known as high level design that focuses on the design of system architecture.
It describes the structure and behavior of the system. It defines the structure and
relationship between various modules of system development process.

Detailed Design
It follows Architectural design and focuses on development of each module.

Conceptual Data Modeling

It is representation of organizational data which includes all the major entities and
relationship. System analysts develop a conceptual data model for the current system
that supports the scope and requirement for the proposed system.

The main aim of conceptual data modeling is to capture as much meaning of data as
possible. Most organization today use conceptual data modeling using E-R model which
uses special notation to represent as much meaning about data as possible.

Entity Relationship Model

It is a technique used in database design that helps describe the relationship between
various entities of an organization.

Terms used in E-R model

 ENTITY − It specifies distinct real world items in an application. For example: vendor, item,
student, course, teachers, etc.

 RELATIONSHIP − They are the meaningful dependencies between entities. For example,
vendor supplies items, teacher teaches courses, then supplies and course are relationship.

 ATTRIBUTES − It specifies the properties of relationships. For example, vendor code,

student name. Symbols used in E-R model and their respective meanings −

The following table shows the symbols used in E-R model and their significance −

Symbol Meaning

Entity
 Weak Entity

Relationship

Identity
Relationship

Attributes

Key Attributes

Multivalued

Composite
Attribute

Derived Attributes
 Total Participation
of E2 in R

Cardinality Ratio
1:N for E1:E2 in R

Three types of relationships can exist between two sets of data: one-to-one, one-to-
many, and many-to-many.

File Organization
It describes how records are stored within a file.

There are four file organization methods −

 Serial − Records are stored in chronological order (in order as they are input or
occur). Examples − Recording of telephone charges, ATM transactions, Telephone queues.

 Sequential − Records are stored in order based on a key field which contains a value that
uniquely identifies a record. Examples − Phone directories.

 Direct (relative) − Each record is stored based on a physical address or location on the
device. Address is calculated from the value stored in the record’s key field. Randomizing
routine or hashing algorithm does the conversion.

 Indexed − Records can be processed both sequentially and non-sequentially using indexes.

Comparision
File Access
One can access a file using either Sequential Access or Random Access. File Access
methods allow computer programs read or write records in a file.

Sequential Access
Every record on the file is processed starting with the first record until End of File (EOF)
is reached. It is efficient when a large number of the records on the file need to be
accessed at any given time. Data stored on a tape (sequential access) can be accessed
only sequentially.

Direct (Random) Access

Records are located by knowing their physical locations or addresses on the device
rather than their positions relative to other records. Data stored on a CD device (direct-
access) can be accessed either sequentially or randomly.

Types of Files used in an Organization System

Following are the types of files used in an organization system −

 Master file − It contains the current information for a system. For example, customer file,
student file, telephone directory.

 Table file − It is a type of master file that changes infrequently and stored in a tabular
format. For example, storing Zipcode.

 Transaction file − It contains the day-to-day information generated from business activities.
It is used to update or process the master file. For example, Addresses of the employees.

 Temporary file − It is created and used whenever needed by a system.

  Mirror file − They are the exact duplicates of other files. Help minimize the risk of downtime
in cases when the original becomes unusable. They must be modified each time the original
file is changed.

 Log files − They contain copies of master and transaction records in order to chronicle any
changes that are made to the master file. It facilitates auditing and provides mechanism for
recovery in case of system failure.

 Archive files − Backup files that contain historical versions of other files.

Documentation Control
Documentation is a process of recording the information for any reference or
operational purpose. It helps users, managers, and IT staff, who require it. It is
important that prepared document must be updated on regular basis to trace the
progress of the system easily.

After the implementation of system if the system is working improperly, then

documentation helps the administrator to understand the flow of data in the system to
correct the flaws and get the system working.

Programmers or systems analysts usually create program and system documentation.

Systems analysts usually are responsible for preparing documentation to help users
learn the system. In large companies, a technical support team that includes technical
writers might assist in the preparation of user documentation and training materials.

Advantages
 It can reduce system downtime, cut costs, and speed up maintenance tasks.

 It provides the clear description of formal flow of present system and helps to understand the
type of input data and how the output can be produced.

 It provides effective and efficient way of communication between technical and nontechnical
users about system.

 It facilitates the training of new user so that he can easily understand the flow of system.

 It helps the user to solve the problems such as troubleshooting and helps the manager to
take better final decisions of the organization system.

 It provides better control to the internal or external working of the system.

Types of Documentations
When it comes to System Design, there are following four main documentations −

 Program documentation
  System documentation

 Operations documentation

 User documentation

Program Documentation
 It describes inputs, outputs, and processing logic for all the program modules.

 The program documentation process starts in the system analysis phase and continues during
implementation.

 This documentation guides programmers, who construct modules that are well supported by
internal and external comments and descriptions that can be understood and maintained
easily.

Operations Documentation
Operations documentation contains all the information needed for processing and
distributing online and printed output. Operations documentation should be clear,
concise, and available online if possible.

It includes the following information −

 Program, systems analyst, programmer, and system identification.

 Scheduling information for printed output, such as report, execution frequency, and deadlines.

 Input files, their source, output files, and their destinations.

 E-mail and report distribution lists.

 Special forms required, including online forms.

 Error and informational messages to operators and restart procedures.

 Special instructions, such as security requirements.

User Documentation
It includes instructions and information to the users who will interact with the system.
For example, user manuals, help guides, and tutorials. User documentation is valuable
in training users and for reference purpose. It must be clear, understandable, and
readily accessible to users at all levels.

The users, system owners, analysts, and programmers, all put combined efforts to
develop a user’s guide.

A user documentation should include −

  A system overview that clearly describes all major system features, capabilities, and
limitations.

 Description of source document content, preparation, processing, and, samples.

 Overview of menu and data entry screen options, contents, and processing instructions.

 Examples of reports that are produced regularly or available at the user’s request, including
samples.

 Security and audit trail information.

 Explanation of responsibility for specific input, output, or processing requirements.

 Procedures for requesting changes and reporting problems.

 Examples of exceptions and error situations.

 Frequently asked questions (FAQs).

 Explanation of how to get help and procedures for updating the user manual.

System Documentation
System documentation serves as the technical specifications for the IS and how the
objectives of the IS are accomplished. Users, managers and IS owners need never
reference system documentation. System documentation provides the basis for
understanding the technical aspects of the IS when modifications are made.

 It describes each program within the IS and the entire IS itself.

 It describes the system’s functions, the way they are implemented, each program's purpose
within the entire IS with respect to the order of execution, information passed to and from
programs, and overall system flow.

 It includes data dictionary entries, data flow diagrams, object models, screen layouts, source
documents, and the systems request that initiated the project.

 Most of the system documentation is prepared during the system analysis and system design
phases.

 During systems implementation, an analyst must review system documentation to verify that
it is complete, accurate, and up-to-date, and including any changes made during the
implementation process.

Top-Down Strategy
The top-down strategy uses the modular approach to develop the design of a system. It
is called so because it starts from the top or the highest-level module and moves
towards the lowest level modules.
In this technique, the highest-level module or main module for developing the software
is identified. The main module is divided into several smaller and simpler submodules or
segments based on the task performed by each module. Then, each submodule is
further subdivided into several submodules of next lower level. This process of dividing
each module into several submodules continues until the lowest level modules, which
cannot be further subdivided, are not identified.

Bottom-Up Strategy
Bottom-Up Strategy follows the modular approach to develop the design of the system.
It is called so because it starts from the bottom or the most basic level modules and
moves towards the highest level modules.

In this technique,

 The modules at the most basic or the lowest level are identified.

 These modules are then grouped together based on the function performed by each module to
form the next higher-level modules.

 Then, these modules are further combined to form the next higher-level modules.

 This process of grouping several simpler modules to form higher level modules continues until
the main module of system development process is achieved.

Structured Design
Structured design is a data-flow based methodology that helps in identifying the input
and output of the developing system. The main objective of structured design is to
minimize the complexity and increase the modularity of a program. Structured design
also helps in describing the functional aspects of the system.

In structured designing, the system specifications act as a basis for graphically

representing the flow of data and sequence of processes involved in a software
development with the help of DFDs. After developing the DFDs for the software system,
the next step is to develop the structure chart.

Modularization
Structured design partitions the program into small and independent modules. These
are organized in top down manner with the details shown in bottom.

Thus, structured design uses an approach called Modularization or decomposition to

minimize the complexity and to manage the problem by subdividing it into smaller
segments.

Advantages

 Critical interfaces are tested first.

 It provide abstraction.

 It allows multiple programmers to work simultaneously.

 It allows code reuse.

 It provides control and improves morale.

 It makes identifying structure easier.

Structured Charts
Structured charts are a recommended tool for designing a modular, top down systems
which define the various modules of system development and the relationship between
each module. It shows the system module and their relationship between them.

It consists of diagram consisting of rectangular boxes that represent the modules,

connecting arrows, or lines.

 Control Module − It is a higher-level module that directs lower-level modules,

called subordinate modules.

 Library Module − It is a reusable module and can be invoked from more than one point in
the chart.

We have two different approaches to design a structured chart −

 Transform-Centered Structured Charts − They are used when all the transactions follow
same path.

 Transaction–Centered Structured Charts − They are used when all the transactions do
not follow the same path.

Objectives of Using Structure Flowcharts

 To encourage a top-down design.

 To support the concept of modules and identify the appropriate modules.

 To show the size and complexity of the system.

 To identify the number of readily identifiable functions and modules within each function.

 To depict whether each identifiable function is a manageable entity or should be broken down
into smaller components.

Factors Affecting System Complexity

To develop good quality of system software, it is necessary to develop a good design.
Therefore, the main focus on while developing the design of the system is the quality of
the software design. A good quality software design is the one, which minimizes the
complexity and cost expenditure in software development.

The two important concepts related to the system development that help in determining
the complexity of a system are coupling and cohesion.

Coupling
Coupling is the measure of the independence of components. It defines the degree of
dependency of each module of system development on the other. In practice, this
means the stronger the coupling between the modules in a system, the more difficult it
is to implement and maintain the system.

Each module should have simple, clean interface with other modules, and that the
minimum number of data elements should be shared between modules.

High Coupling
These type of systems have interconnections with program units dependent on each
other. Changes to one subsystem leads to high impact on the other subsystem.

Low Coupling
These type of systems are made up of components which are independent or almost
independent. A change in one subsystem does not affect any other subsystem.
Coupling Measures
 Content Coupling − When one component actually modifies another,then the modified
component is completely dependent on modifying one.

 Common Coupling − When amount of coupling is reduced somewhat by organizing system

design so that data are accessible from a common data store.

 Control Coupling − When one component passes parameters to control the activity of
another component.

 Stamp Coupling − When data structures is used to pass information from one component to
another.

 Data Coupling − When only data is passed then components are connected by this coupling.

Cohesion
Cohesion is the measure of closeness of the relationship between its components. It
defines the amount of dependency of the components of a module on one another. In
practice, this means the systems designer must ensure that −

 They do not split essential processes into fragmented modules.

 They do not gather together unrelated processes represented as processes on the DFD into
meaningless modules.

The best modules are those that are functionally cohesive. The worst modules are those
that are coincidentally cohesive.

The worst degree of cohesion

Coincidental cohesion is found in a component whose parts are unrelated to another.

 Logical Cohesion − It is where several logically related functions or data elements are
placed in same component.
  Temporal Cohesion − It is when a component that is used to initialize a system or set
variables performs several functions in sequence, but the functions are related by timing
involved.

 Procedurally Cohesion − It is when functions are grouped together in a component just to

ensure this order.

 Sequential Cohesion − It is when the output from one part of a component is the input to
the next part of it.

Input Design
In an information system, input is the raw data that is processed to produce output.
During the input design, the developers must consider the input devices such as PC,
MICR, OMR, etc.

Therefore, the quality of system input determines the quality of system output.
Welldesigned input forms and screens have following properties −

 It should serve specific purpose effectively such as storing, recording, and retrieving the
information.

 It ensures proper completion with accuracy.

 It should be easy to fill and straightforward.

 It should focus on user’s attention, consistency, and simplicity.

 All these objectives are obtained using the knowledge of basic design principles regarding −

o What are the inputs needed for the system?

o How end users respond to different elements of forms and screens.

Objectives for Input Design

The objectives of input design are −

 To design data entry and input procedures

 To reduce input volume

 To design source documents for data capture or devise other data capture methods

 To design input data records, data entry screens, user interface screens, etc.

 To use validation checks and develop effective input controls.

Data Input Methods

It is important to design appropriate data input methods to prevent errors while
entering data. These methods depend on whether the data is entered by customers in
forms manually and later entered by data entry operators, or data is directly entered by
users on the PCs.

A system should prevent user from making mistakes by −

 Clear form design by leaving enough space for writing legibly.

 Clear instructions to fill form.

 Clear form design.

 Reducing key strokes.

 Immediate error feedback.

Some of the popular data input methods are −

 Batch input method (Offline data input method)

 Online data input method

 Computer readable forms

 Interactive data input

Input Integrity Controls

Input integrity controls include a number of methods to eliminate common input errors
by end-users. They also include checks on the value of individual fields; both for format
and the completeness of all inputs.

Audit trails for data entry and other system operations are created using transaction
logs which gives a record of all changes introduced in the database to provide security
and means of recovery in case of any failure.

Output Design
The design of output is the most important task of any system. During output design,
developers identify the type of outputs needed, and consider the necessary output
controls and prototype report layouts.

Objectives of Output Design

The objectives of input design are −

 To develop output design that serves the intended purpose and eliminates the production of
unwanted output.

 To develop the output design that meets the end users requirements.
  To deliver the appropriate quantity of output.

 To form the output in appropriate format and direct it to the right person.

 To make the output available on time for making good decisions.

Let us now go through various types of outputs −

External Outputs
Manufacturers create and design external outputs for printers. External outputs enable
the system to leave the trigger actions on the part of their recipients or confirm actions
to their recipients.

Some of the external outputs are designed as turnaround outputs, which are
implemented as a form and re-enter the system as an input.

Internal outputs
Internal outputs are present inside the system, and used by end-users and managers.
They support the management in decision making and reporting.

There are three types of reports produced by management information −

 Detailed Reports − They contain present information which has almost no filtering or
restriction generated to assist management planning and control.

 Summary Reports − They contain trends and potential problems which are categorized and
summarized that are generated for managers who do not want details.

 Exception Reports − They contain exceptions, filtered data to some condition or standard
before presenting it to the manager, as information.

Output Integrity Controls

Output integrity controls include routing codes to identify the receiving system, and
verification messages to confirm successful receipt of messages that are handled by
network protocol.

Printed or screen-format reports should include a date/time for report printing and the
data. Multipage reports contain report title or description, and pagination. Pre-printed
forms usually include a version number and effective date.

Forms Design
Both forms and reports are the product of input and output design and are business
document consisting of specified data. The main difference is that forms provide fields
for data input but reports are purely used for reading. For example, order forms,
employment and credit application, etc.

 During form designing, the designers should know −

 o who will use them

o where would they be delivered

o the purpose of the form or report

 During form design, automated design tools enhance the developer’s ability to prototype
forms and reports and present them to end users for evaluation.

Objectives of Good Form Design

A good form design is necessary to ensure the following −

 To keep the screen simple by giving proper sequence, information, and clear captions.

 To meet the intended purpose by using appropriate forms.

 To ensure the completion of form with accuracy.

 To keep the forms attractive by using icons, inverse video, or blinking cursors etc.

 To facilitate navigation.

Types of Forms
Flat Forms

 It is a single copy form prepared manually or by a machine and printed on a paper. For
additional copies of the original, carbon papers are inserted between copies.

 It is a simplest and inexpensive form to design, print, and reproduce, which uses less volume.

Unit Set/Snap out Forms

 These are papers with one-time carbons interleaved into unit sets for either handwritten or
machine use.

 Carbons may be either blue or black, standard grade medium intensity. Generally, blue
carbons are best for handwritten forms while black carbons are best for machine use.

Continuous strip/Fanfold Forms

 These are multiple unit forms joined in a continuous strip with perforations between each pair
of forms.

 It is a less expensive method for large volume use.

No Carbon Required (NCR) Paper

 They use carbonless papers which have two chemical coatings (capsules), one on the face and
the other on the back of a sheet of paper.

 When pressure is applied, the two capsules interact and create an image.
The software system needs to be checked for its intended behavior and direction of
progress at each development stage to avoid duplication of efforts, time and cost
overruns, and to assure completion of the system within stipulated time.The software
system needs to be checked for its intended behavior and direction of progress at each
development stage to avoid duplication of efforts, time and cost overruns, and to
assure completion of the system within stipulated time.

System testing and quality assurance come to aid for checking the system. It includes
−

 Product level quality (Testing)

 Process level quality.

Let us go through them briefly −

Testing
Testing is the process or activity that checks the functionality and correctness of
software according to specified user requirements in order to improve the quality and
reliability of system. It is an expensive, time consuming, and critical approach in
system development which requires proper planning of overall testing process.

A successful test is one that finds the errors. It executes the program with explicit
intention of finding error, i.e., making the program fail. It is a process of evaluating
system with an intention of creating a strong system and mainly focuses on the weak
areas of the system or software.

Characteristics of System Testing

System testing begins at the module level and proceeds towards the integration of the
entire software system. Different testing techniques are used at different times while
testing the system. It is conducted by the developer for small projects and by
independent testing groups for large projects.

Stages of System Testing

The following stages are involved in testing −

Test Strategy

It is a statement that provides information about the various levels, methods, tools,
and techniques used for testing the system. It should satisfy all the needs of an
organization.

Test Plan
It provides a plan for testing the system and verifies that the system under testing
fulfils all the design and functional specifications. The test plan provides the following
information −

 Objectives of each test phase

 Approaches and tools used for testing

 Responsibilities and time required for each testing activity

 Availability of tools, facilities, and test libraries

 Procedures and standards required for planning and conducting the tests

 Factors responsible for successful completion of testing process

Test Case Design

 Test cases are used to uncover as many errors as possible in the system.

 A number of test cases are identified for each module of the system to be tested.

 Each test case will specify how the implementation of a particular requirement or design
decision is to be tested and the criteria for the success of the test.

 The test cases along with the test plan are documented as a part of a system specification
document or in a separate document called test specification or test description.

Test Procedures

It consists of the steps that should be followed to execute each of the test cases. These
procedures are specified in a separate document called test procedure specification.
This document also specifies any special requirements and formats for reporting the
result of testing.

Test Result Documentation

Test result file contains brief information about the total number of test cases executed,
the number of errors, and nature of errors. These results are then assessed against
criteria in the test specification to determine the overall outcome of the test.

Types of Testing
Testing can be of various types and different types of tests are conducted depending on
the kind of bugs one seeks to discover −

Unit Testing
Also known as Program Testing, it is a type of testing where the analyst tests or focuses
on each program or module independently. It is carried out with the intention of
executing each statement of the module at least once.

 In unit testing, accuracy of program cannot be assured and it is difficult to conduct testing of
various input combination in detail.

 It identifies maximum errors in a program as compared to other testing techniques.

Integration Testing
In Integration Testing, the analyst tests multiple module working together. It is used to
find discrepancies between the system and its original objective, current specifications,
and systems documentation.

 Here the analysts are try to find areas where modules have been designed with different
specifications for data length, type, and data element name.

 It verifies that file sizes are adequate and that indices have been built properly.

Functional Testing
Function testing determines whether the system is functioning correctly according to its
specifications and relevant standards documentation. Functional testing typically starts
with the implementation of the system, which is very critical for the success of the
system.

Functional testing is divided into two categories −

 Positive Functional Testing − It involves testing the system with valid inputs to verify that
the outputs produced are correct.

 Negative Functional Testing − It involves testing the software with invalid inputs and
undesired operating conditions.

Rules for System Testing

To carry out system testing successfully, you need to follow the given rules −

 Testing should be based on the requirements of user.

 Before writing testing scripts, understand the business logic should be understood thoroughly.

 Test plan should be done as soon as possible.

 Testing should be done by the third party.

 It should be performed on static software.

 Testing should be done for valid and invalid input conditions.

 Testing should be reviewed and examined to reduce the costs.

  Both static and dynamic testing should be conducted on the software.

 Documentation of test cases and test results should be done.

Quality Assurance
It is the review of system or software products and its documentation for assurance
that system meets the requirements and specifications.

 Purpose of QA is to provide confidence to the customers by constant delivery of product

according to specification.

 Software quality Assurance (SQA) is a techniques that includes procedures and tools applied
by the software professionals to ensure that software meet the specified standard for its
intended use and performance.

 The main aim of SQA is to provide proper and accurate visibility of software project and its
developed product to the administration.

 It reviews and audits the software product and its activities throughout the life cycle of
system development.

Objectives of Quality Assurance

The objectives of conducting quality assurance are as follows −

 To monitor the software development process and the final software developed.

 To ensure whether the software project is implementing the standards and procedures set by
the management.

 To notify groups and individuals about the SQA activities and results of these activities.

 To ensure that the issues, which are not solved within the software are addressed by the
upper management.

 To identify deficiencies in the product, process, or the standards, and fix them.

Levels of Quality Assurance

There are several levels of QA and testing that need to be performed in order to certify
a software product.

Level 1 − Code Walk-through

At this level, offline software is examined or checked for any violations of the official
coding rules. In general, the emphasis is placed on examination of the documentation
and level of in-code comments.

Level 2 − Compilation and Linking

At this level, it is checked that the software can compile and link all official platforms
and operating systems.

Level 3 − Routine Running

At this level, it is checked that the software can run properly under a variety of
conditions such as certain number of events and small and large event sizes etc.

Level 4 − Performance test

At this final level, it is checked that the performance of the software satisfies the
previously specified performance level.

Implementation is a process of ensuring that the information system is operational. It

involves −

 Constructing a new system from scratch

 Constructing a new system from the existing one.

System Implementation and Maintenance

Implementation allows the users to take over its operation for use and evaluation. It
involves training the users to handle the system and plan for a smooth conversion.

Training
The personnel in the system must know in detail what their roles will be, how they can
use the system, and what the system will or will not do. The success or failure of
welldesigned and technically elegant systems can depend on the way they are operated
and used.

Training Systems Operators

Systems operators must be trained properly such that they can handle all possible
operations, both routine and extraordinary. The operators should be trained in what
common malfunctions may occur, how to recognize them, and what steps to take when
they come.

Training involves creating troubleshooting lists to identify possible problems and

remedies for them, as well as the names and telephone numbers of individuals to
contact when unexpected or unusual problems arise.

Training also involves familiarization with run procedures, which involves working
through the sequence of activities needed to use a new system.
User Training
 End-user training is an important part of the computer-based information system
development, which must be provided to employees to enable them to do their own problem
solving.

 User training involves how to operate the equipment, troubleshooting the system problem,
determining whether a problem that arose is caused by the equipment or software.

 Most user training deals with the operation of the system itself. The training courses must be
designed to help the user with fast mobilization for the organization.

Training Guidelines

 Establishing measurable objectives

 Using appropriate training methods

 Selecting suitable training sites

 Employing understandable training materials

Training Methods
Instructor-led training
It involves both trainers and trainees, who have to meet at the same time, but not
necessarily at the same place. The training session could be one-on-one or
collaborative. It is of two types −

Virtual Classroom

In this training, trainers must meet the trainees at the same time, but are not required
to be at the same place. The primary tools used here are: video conferencing, text
based Internet relay chat tools, or virtual reality packages, etc.

Normal Classroom

The trainers must meet the trainees at the same time and at the same place. They
primary tools used here are blackboard, overhead projectors, LCD projector, etc.

Self-Paced Training
It involves both trainers and trainees, who do not need to meet at the same place or at
the same time. The trainees learn the skills themselves by accessing the courses at
their own convenience. It is of two types −

Multimedia Training
In this training, courses are presented in multimedia format and stored on CD-ROM. It
minimizes the cost in developing an in-house training course without assistance from
external programmers.

Web-based Training

In this training, courses are often presented in hyper media format and developed to
support internet and intranet. It provides just–in-time training for end users and allow
organization to tailor training requirements.

Conversion
It is a process of migrating from the old system to the new one. It provides
understandable and structured approach to improve the communication between
management and project team.

Conversion Plan
It contains description of all the activities that must occur during implementation of the
new system and put it into operation. It anticipates possible problems and solutions to
deal with them.

It includes the following activities −

 Name all files for conversions.

 Identifying the data requirements to develop new files during conversion.

 Listing all the new documents and procedures that are required.

 Identifying the controls to be used in each activity.

 Identifying the responsibility of person for each activity.

 Verifying conversion schedules.

Conversion Methods
The four methods of conversion are −

 Parallel Conversion

 Direct Cutover Conversion

 Pilot Approach

 Phase-In Method
 Method Description Advantages Disadvantages

Provides Causes cost

fallback when overruns.
new system
New system
Old and new fails.
may not get
Parallel systems are
used Offers greatest fair trail.
Conversion
simultaneously. security and
ultimately
testing of new
system.

Forces users to No fall back if

New system is make new problems arise

Direct implemented system work with new

Cutover and old system system

Immediate
Conversion is replaced benefit from Requires most
completely. new methods careful planning
and control.

Allows training A long term

and installation phasein causes
Supports
without a problem of
phased
unnecessary whether
approach that
Pilot use of conversion
gradually
Approach resources. goes well or
implement
not.
Avoid large
system across
contingencies
all users
from risk
management.

Phase-In Working Provides Gives

Method version of experience and impression that
system line test before old system is
implemented in implementation erroneous and
one part of it is not
When preferred
organization reliable.
new system
 based on involves new
feedback, it is technology or
installed drastic changes
throughout the in performance.
organization all
alone or stage
by stage.

File Conversion
It is a process of converting one file format into another. For example, file in
WordPerfect format can be converted into Microsoft Word.

For successful conversion, a conversion plan is required, which includes −

 Knowledge of the target system and understanding of the present system

 Teamwork

 Automated methods, testing and parallel operations

 Continuous support for correcting problems

 Updating systems/user documentation, etc

Many popular applications support opening and saving to other file formats of the same
type. For example, Microsoft Word can open and save files in many other word
processing formats.

Post-Implementation Evaluation Review (PIER)

PIER is a tool or standard approach for evaluating the outcome of the project and
determine whether the project is producing the expected benefits to the processes,
products or services. It enables the user to verify that the project or system has
achieved its desired outcome within specified time period and planned cost.

PIER ensures that the project has met its goals by evaluating the development and
management processes of the project.

Objectives of PIER
The objectives of having a PIER are as follows −

 To determine the success of a project against the projected costs, benefits, and timelines.

 To identify the opportunities to add additional value to the project.

  To determine strengths and weaknesses of the project for future reference and appropriate
action.

 To make recommendations on the future of the project by refining cost estimating techniques.

The following staff members should be included in the review process −

 Project team and Management

 User staff

 Strategic Management Staff

 External users

System Maintenance / Enhancement

Maintenance means restoring something to its original conditions. Enhancement means
adding, modifying the code to support the changes in the user specification. System
maintenance conforms the system to its original requirements and enhancement adds
to system capability by incorporating new requirements.

Thus, maintenance changes the existing system, enhancement adds features to the
existing system, and development replaces the existing system. It is an important part
of system development that includes the activities which corrects errors in system
design and implementation, updates the documents, and tests the data.

Maintenance Types
System maintenance can be classified into three types −

 Corrective Maintenance − Enables user to carry out the repairing and correcting leftover
problems.

 Adaptive Maintenance − Enables user to replace the functions of the programs.

 Perfective Maintenance − Enables user to modify or enhance the programs according to

the users’ requirements and changing needs.

System Security and Audit

System Audit
It is an investigation to review the performance of an operational system. The
objectives of conducting a system audit are as follows −
  To compare actual and planned performance.

 To verify that the stated objectives of system are still valid in current environment.

 To evaluate the achievement of stated objectives.

 To ensure the reliability of computer based financial and other information.

 To ensure all records included while processing.

 To ensure protection from frauds.

Audit of Computer System Usage

Data processing auditors audits the usage of computer system in order to control it.
The auditor need control data which is obtained by computer system itself.

The System Auditor

The role of auditor begins at the initial stage of system development so that resulting
system is secure. It describes an idea of utilization of system that can be recorded
which helps in load planning and deciding on hardware and software specifications. It
gives an indication of wise use of the computer system and possible misuse of the
system.

Audit Trial
An audit trial or audit log is a security record which is comprised of who has accessed a
computer system and what operations are performed during a given period of time.
Audit trials are used to do detailed tracing of how data on the system has changed.

It provides documentary evidence of various control techniques that a transaction is

subject to during its processing. Audit trials do not exist independently. They are
carried out as a part of accounting for recovering lost transactions.

Audit Methods
Auditing can be done in two different ways −

Auditing around the Computer

 Take sample inputs and manually apply processing rules.

 Compare outputs with computer outputs.

Auditing through the Computer

 Establish audit trial which allows examining selected intermediate results.

 Control totals provide intermediate checks.

Audit Considerations
Audit considerations examine the results of the analysis by using both the narratives
and models to identify the problems caused due to misplaced functions, split processes
or functions, broken data flows, missing data, redundant or incomplete processing, and
nonaddressed automation opportunities.

The activities under this phase are as follows −

 Identification of the current environment problems

 Identification of problem causes

 Identification of alternative solutions

 Evaluation and feasibility analysis of each solution

 Selection and recommendation of most practical and appropriate solution

 Project cost estimation and cost benefit analysis

Security
System security refers to protecting the system from theft, unauthorized access and
modifications, and accidental or unintentional damage. In computerized systems,
security involves protecting all the parts of computer system which includes data,
software, and hardware. Systems security includes system privacy and system
integrity.

 System privacy deals with protecting individuals systems from being accessed and used
without the permission/knowledge of the concerned individuals.

 System integrity is concerned with the quality and reliability of raw as well as processed
data in the system.

Control Measures
There are variety of control measures which can be broadly classified as follows −

Backup
 Regular backup of databases daily/weekly depending on the time criticality and size.

 Incremental back up at shorter intervals.

 Backup copies kept in safe remote location particularly necessary for disaster recovery.

 Duplicate systems run and all transactions mirrored if it is a very critical system and cannot
tolerate any disruption before storing in disk.
Physical Access Control to Facilities

 Physical locks and Biometric authentication. For example, finger print

 ID cards or entry passes being checked by security staff.

 Identification of all persons who read or modify data and logging it in a file.

Using Logical or Software Control

 Password system.

 Encrypting sensitive data/programs.

 Training employees on data care/handling and security.

 Antivirus software and Firewall protection while connected to internet.

Risk Analysis
A risk is the possibility of losing something of value. Risk analysis starts with planning
for secure system by identifying the vulnerability of system and impact of this. The plan
is then made to manage the risk and cope with disaster. It is done to accesses the
probability of possible disaster and their cost.

Risk analysis is a teamwork of experts with different backgrounds like chemicals,

human error, and process equipment.

The following steps are to be followed while conducting risk analysis −

 Identification of all the components of computer system.

 Identification of all the threats and hazards that each of the components faces.

 Quantify risks i.e. assessment of loss in the case threats become reality.

Risk Analysis – Main Steps

As the risks or threats are changing and the potential loss are also changing,
management of risk should be performed on periodic basis by senior managers.
Risk management is a continuous process and it involves the following steps −

 Identification of security measures.

 Calculation of the cost of implementation of security measures.

 Comparison of the cost of security measures with the loss and probability of threats.

 Selection and implementation of security measures.

 Review of the implementation of security measures.