SCSD2613

 
System Analysis and
Design  

PART  1  
Fundamentals  of  Systems  
Analysis  &  Design  
  1  
 Learning  Objec-ves  
•  By  the  end  of  this  lecture,  you  will  be  able  to:  
•  Recall  the  basic  types  of  computer-­‐based  systems  that  a  systems  analyst  
needs  to  address  
•  Understand  how  users  working  in  context  with  new  technologies  change  
the  dynamics  of  a  system  
•  Realize  what  the  many  roles  of  the  systems  analyst  are  
•  Know  the  steps  of  the  SDLC  as  they  relate  to  HCI  and  how  to  apply  them  
to  a  real  system  
•  Understand  what  CASE  tools  are  and  how  they  help  a  systems  analyst  
•  Explore  other  methodologies  such  as  object-­‐oriented  systems  design  and  
prototyping  

2  
 Informa-on  –  A  Key  Resource  
•  Fuels  business  and  can  be  the  criOcal  factor  in  
determining  the  success  or  failure  of  a  
business  
•  Needs  to  be  managed  correctly  
•  Managing  computer-­‐generated  informaOon  
differs  from  handling  manually  produced  data  

3  
 What is Information
Systems (IS)?
…Buckingham et al. (1987)

A system which assembles, stores,

processes and delivers information relevant
to an organization, in such a way that the
information is accessible and useful to those
who wish to use it, including managers,
staff, clients and citizens. An IS is human
activity (social system) which may or may
not involve the use of computer systems

(Computerized)  
(in  this  case)   Informa-on    
Systems   4  
What and Why ISD ???
Systems analysis and design is a
systematic approach to identifying
problems, opportunities, and objectives;
analyzing the information flows in
organizations; and designing
computerized (in this case) information
systems to solve a problem

(Computerized)  
Informa-on    
Systems  

5  
 What  and  Why  ISD  ?  
•  System  development  needs  proper  planning.  
•  There  is  a  cost  in  system  development.  
•  It  is  Ome  consuming  and  needs  project  
management.  
•  SADM  is  about  problem  solving  that  needs  to  
be  creaOve,  criOcal,  and  innovaOve.  

6  
 Organiza-on  as  Systems  
•  OrganizaOon  as  systems,  is  composed  of  subsystems  
and  so  on.  
•  It  is  mainly  involves  levels  of  management  and  
culture.  
•  These  will  impact  the  informaOon  system  
development.  
•  The  different  levels  of  management  will  produce  the  
different  levels  of  decisions.  
•  The  culture  influences  the  way  people  in  subsystems  
interrelate.  
7  
 Organization as
Systems

Goals  
OUTPUT
/INPUT

STUDENT  AFFAIR  

FACULTY  

OUTPUT
/INPUT 8  
  
6  Generic    
Components  
  SYSTEM
Processing

Control

Boundary Output
Input
Feedback

Data People
   
Data People
6  Generic     6  Generic    
+ Components   Hardware Software + Components  
   
Procedures
Procedures

Information Systems Automated Information

Systems
9  
 Organizations as
Systems> Levels of
Management

What ?
Strategic
Mgt

Tactical Mgt
How ?

Operations Mgt
Implement ?
10  
 Production system (super-system)

System: a
collection of
Inventory    
interrelated
management    
components that
system  
function together to
achieve some Manufacturing    
outcome System  
Information
System: a
collection of
interrelated
 
components that  
collect, process, Customer    
Order-­‐entry    
store, and provide maintenance    
subsystem  
as output the subsystem  
Customer      
information needed  
to complete support    
business tasks.
  system    
Catalog     Order    
Sub-system: a maintenance     fulfillment    
system that is part
of a larger system
subsystem   subsystem  
   
Super-system: a
larger system that
contains other 11  
systems
 A Framework
For ISD

12  
 Business  Drivers  for  Today’s  
Informa-on  Systems  
•  GlobalizaOon  of  the  Economy  
•  Electronic  Commerce  and  Business  
•  Security  and  Privacy  
•  CollaboraOon  and  Partnership  
•  Knowledge  Asset  Management  
•  ConOnuous  Improvement  and  Total  Quality  
Management  
•  Business  Process  Redesign  
13  
 Business  Drivers  for  Today’s  
Informa-on  Systems  
•  Networks  and  the  Internet  
•  Mobile  and  Wireless  Technologies  
•  Object  Technologies  
•  CollaboraOve  Technologies  
•  Enterprise  ApplicaOons  

14  
 Major  Topics  
•  Fundamentals  of  different  kinds  of  
informaOon  systems  
•  Roles  of  systems  analysts  
•  Phases  in  the  systems  development  life  cycle  
as  they  relate  to  Human-­‐Computer  InteracOon  
(HCI)  factors  
•  Computer-­‐Aided  Sodware  Engineering  (CASE)  
tools  
15  
 Systems  Analysts  Recommend,  
Design,  and  Maintain  Many  Types  of  
Systems  for  Users  
–  TransacOon  Processing  Systems  (TPS)  
–  Office  AutomaOon  Systems  (OAS)  
–  Knowledge  Work  Systems  (KWS)  
–  Management  InformaOon  Systems  (MIS)  
–  Decision  Support  Systems  (DSS)  
–  Expert  Systems  (ES)  
–  ExecuOve  Support  Systems  (ESS)  
–  Group  Decision  Support  Systems  (GDSS)  
–  Computer-­‐Supported  CollaboraOve  Work  Systems  
(CSCWS)  

16  
 A systems analyst
may be involved with
Strategic  
Level  
any or all of these
systems at each
organization level
Higher  Level  

Knowledge  
Level  

OperaOonal  
Level  

17  
 Opera-onal  Level  
•  TransacOon  Processing  System  (TPS)  
–  Process  large  amounts  of  data  for  rouOne  business  
transacOons  
–  Boundary-­‐spanning  
–  Support  the  day-­‐to-­‐day  operaOons  of  the  company  
–  Examples:  Payroll  Processing,  Inventory  Management  

18  
 A  Payroll  TPS  
 

A  TPS  for  payroll  processing  

captures  employee  payment  
transacOon  data  (such  as  a  
Ome  card).  System  outputs  
include  online  and  hard-­‐copy  
reports  for  management  and  
employee  paychecks.  
 Knowledge  Level  
•  Office  AutomaOon  System  (OAS)  
–  Supports  data  workers  who  share  informaOon,  but  do  not  usually  
create  new  knowledge  
–  Examples:  Word  processing,  Spreadsheets,  Desktop  publishing,  
Electronic  scheduling,  CommunicaOon  through  voice  mail,  Email,  
Video  conferencing  
•  Knowledge  Work  System  (KWS)  
–  Supports  professional  workers  such  as  scienOsts,  engineers,  and  
doctors  
–  Examples:  computer-­‐aided  design  systems,  virtual  reality  systems,  
investment  workstaOons  

20  
 Higher  Level  
•  Management  InformaOon  System  (MIS)  
–  Support  a  broad  spectrum  of  organizaOonal  tasks  including  decision  
analysis  and  decision  making  
–  Examples:  profit  margin  by  sales  region,  expenses  vs.  budgets  
•  Decision  Support  System  (DSS)  
–  Aids  decision  makers  in  the  making  of  decisions  
–  Examples:  financial  planning  with  what-­‐if  analysis,  budgeOng  with  
modeling  
•  Expert  System  (ES)  
–  Captures  and  uses  the  knowledge  of  an  expert  for  solving  a  parOcular  
problem  which  leads  to  a  conclusion  or  recommendaOon  
–  Examples:  MYCIN,  XCON  

21  
How  MIS  Obtain  Their  Data  from  the  Organiza;on’s  TPS  
 

In  the  system  illustrated  by  this  diagram,  three  TPS  supply  summarized  transacOon  data  to  the  MIS  reporOng  
system  at  the  end  of  the  Ome  period.  Managers  gain  access  to  the  organizaOonal  data  through  the  MIS,  which  
provides  them  with  the  appropriate  reports.  
 
 Voyage-­‐Es;ma;ng  Decision  Support  System  
 

This  DSS  operates  on  a  powerful  PC.  It  is  used  daily  by  managers  who  must  develop  bids  on  shipping  
contracts.  
 Strategic  Level  
•  ExecuOve  Support  System  (ESS)  
–  Helps  execuOves  to  make  unstructured  strategic  decisions  in  an  
informed  way  
–  Examples:  drill-­‐down  analysis,  status  access  
•  Group  Decision  Support  System  (GDSS)  
–  Permit  group  members  to  interact  with  electronic  support  
–  Examples:  email,  Lotus  Notes  
•  Computer-­‐Supported  CollaboraOve  Work  System  (CSCWS)  
–  CDCWS  is  a  more  general  term  of  GDSS  
–  May  include  sodware  support  called  “groupware”  for  team  
collaboraOon  via  network  computers  
–  Example:  video  conferencing,  Web  survey  system  

24  
 Integra-ng  New  Technologies  
into  Tradi-onal  Systems    
•  Ecommerce  and  Web  Systems  
•  Enterprise  Resource  Planning  Systems  
•  Wireless  Systems  
•  Open  Source  Sodware  
•  Need  for  Systems  Analysis  and  Design  

25  
 Enterprise  Applica;on  Architecture  
 

Enterprise  applicaOons  
automate  processes  that  span  
mulOple  business  funcOons  and  
organizaOonal  levels  and  may  
extend  outside  the  
organizaOon.  
 Systems  analysts  need  to  be  aware  that  
integra-ng  technologies  affects  all  types  of  
systems  

27  
 Ecommerce  and  Web  Systems  
•  Benefits  
–  Increasing  user  awareness  of  the  availability  of  a  service,  
product,  industry,  person,  or  group  
–  The  possibility  of  24-­‐hour  access  for  users  
–  Improving  the  usefulness  and  usability  of  interface  design  
–  CreaOng  a  system  that  can  extend  globally  rather  than  
remain  local,  thus  reaching  people  in  remote  locaOons  
without  worry  of  the  Ome  zone  in  which  they  are  located  

28  
 Enterprise  Resource  Planning  
Systems  (ERP)  
•  Performs  integraOon  of  many  informaOon  
systems  exisOng  on  different  management  
levels  and  within  different  funcOons  
•  Example:  SAP,  Oracle  

29  
 Wireless  Systems  
•  System  analyst  may  be  asked  to  design  standard  or  
wireless  communicaOon  networks  that  integrate  
voice,  video  and  email  into  organizaOonal  intranets  
or  industry  extranets  
•  System  analyst  may  also  be  asked  to  develop  
intelligent  agents  
•  Example:  Microsod's  new  sodware  based  on  
Bayesian  staOsOcs    
•  Wireless  communicaOon  is  referred  as  m-­‐commerce  
(mobile  commerce)  

30  
 Open  Source  SoXware  
•  An  alternaOve  of  tradiOonal  sodware  development  
where  proprietary  code  is  hidden  from  the  users  
•  Open  source  sodware  is  free  to  distribute,  share  and  
modify  
•  Characterized  as  a  philosophy  rather  than  simply  the  
process  of  creaOng  new  sodware  
•  Example:  Linux  OperaOng  System,  Apache  Web  
Server,  Mozilla  Firefox  Web  browser  

31  
 Need  for  Systems  Analysis  and  
Design  
•  Installing  a  system  without  proper  planning  leads  to  
great  user  dissaOsfacOon  and  frequently  causes  the  
system  to  fall  into  disuse  
•  Lends  structure  to  the  analysis  and  design  of  
informaOon  systems  
•  A  series  of  processes  systemaOcally  undertaken  to  
improve  a  business  through  the  use  of  computerized  
informaOon  systems  

32  
System Analyst>Roles &
Environment

System analyst (SA) studies the

problems and needs of an
organization to determine how people,
data, process, communications and
information technology can best
accomplish improvements for the
business (organizations)

(Computerized)  
Informa-on    
Systems  
33  
 Roles  of  the  Systems  Analyst  
•  The  analyst  must  be  able  to  work  with  people  
of  all  descripOons  and  be  experienced  in  
working  with  computers  
•  Three  primary  roles:  
–  Consultant  
–  SupporOng  Expert  
–  Agent  of  change  

34  
 Quali-es  of  the  Systems  Analyst  
•  Problem  solver  
•  Communicator  
•  Strong  personal  and  professional  ethics  
•  Self-­‐disciplined  and  self-­‐moOvated  

35  
 System
Analyst>Roles &
Environment

36  
 Systems  Development  Life  Cycle  
(SDLC)  
•  The  systems  development  life  cycle  is  a  phased  
approach  to  solving  business  problems  
•  Developed  through  the  use  of  a  specific  cycle  of  
analyst  and  user  acOviOes  
•  Each  phase  has  unique  user  acOviOes  

37  
The  seven  phases  of  the  systems  
development  life  cycle  

38  
 Incorpora-ng  Human-­‐Computer  
Interac-on  (HCI)  Considera-ons  
•  The   demand   for   analysts   who   are   capable   of  
i n c o r p o r a O n g   H C I   i n t o   t h e   s y s t e m s  
development   process   keeps   increasing,   as  
companies   begin   to   realize   that   the   quality   of  
systems   and   the   quality   of   work   life   can   be  
improved   by   taking   a   human-­‐centered  
approach  at  the  outset  of  a  project  

39  
 Iden-fying  Problems,  
Opportuni-es,  and  Objec-ves  
•  AcOvity:  
–  Interviewing  user  management  
–  Summarizing  the  knowledge  obtained  
–  EsOmaOng  the  scope  of  the  project  
–  DocumenOng  the  results  
•  Output:          
–  Feasibility  report  containing  problem  definiOon  and  
objecOve  summaries  from  which  management  can  make  a  
decision  on  whether  to  proceed  with  the  proposed  project  
(come  out  with  your  system    proposal)  

40  
 Determining  Human  Informa-on  
Requirements  
•  AcOvity:  
–  Interviewing  
–  Sampling  and  invesOng  hard  data  
–  QuesOonnaires  
–  Observe  the  decision  maker’s  behavior  and  environment  
–  Prototyping  
–  Learn  the  who,  what,  where,  when,  how,  and  why  of  the  current  system  
•  Output:    
–  Analyst  understands  how  users  accomplish  their  work  when  interacOng  
with  a  computer;  and  begin  to  know  how  to  make  the  new  system  more  
useful  and  usable.  The  analyst  should  also  know  the  business  funcOons  
and  have  complete  informaOon  on  the  people,  goals,  data  and  
procedure  involved  

41  
 Analyzing  System  Needs  
•  AcOvity:  
–  Create  data  flow  diagrams    
–  Complete  the  data  dicOonary  
–  Analyze  the  structured  decisions  made  
–  Prepare  and  present  the  system  proposal  
•  Output:    
–  RecommendaOon  on  what,  if  anything,  should  be  
done  

42  
 Designing  the  Recommended  
System  
•  AcOvity:  
–  Design  procedures  for  data  entry  
–  Design  the  human-­‐computer  interface  
–  Design  system  controls  
–  Design  files  and/or  database  
–  Design  backup  procedures  
•  Output  
–  Model  of  the  actual  system    

43  
 Developing  and  Documen-ng  
SoXware  
•  AcOvity:  
–  System  analyst  works  with  programmers  to  develop  any  original  
sodware  
–  Works  with  users  to  develop  effecOve  documentaOon  
–  Programmers  design,  code,  and  remove  syntacOcal  errors  from  
computer  programs  
–  Document  sodware  with  help  files,  procedure  manuals,  and  Web  
sites  with  Frequently  Asked  QuesOons  
•  Output:  
–  Computer  programs  
–  System  documentaOon  

44  
 Tes-ng  and  Maintaining  the  
System  
•  AcOvity:  
–  Test  the  informaOon  system  
–  System  maintenance    
–  Maintenance  documentaOon  
•  Output:  
–  Problems,  if  any  
–  Updated  programs  
–  DocumentaOon  

45  
 Implemen-ng  and  Evalua-ng  the  
System  
•  AcOvity:  
–  Train  users  
–  Analyst  plans  smooth  conversion  from  old  system  
to  new  system  
–  Review  and  evaluate  system  
•  Output:  
–  Trained  personnel  
–  Installed  system  

46  
Figure  1.4  Some  researchers  es-mate  that  the  amount  of  
-me  spent  on  systems  maintenance  may  be  as  much  as  60  
percent  of  the  total  -me  spent  on  systems  projects  

47  
 The  Impact  of  Maintenance  
•  Maintenance  is  performed  for  two  reasons    
–  Removing  sodware  errors,  and  
–  Enhancing  exisOng  sodware  
•  Over  Ome  the  cost  of  conOnued  maintenance  
will  be  greater  than  that  of  creaOng  an  enOrely  
new  system.  At  that  point  it  becomes  more  
feasible  to  perform  a  new  systems  study    

48  
Resource  consump-on  over  
the  system  life  

49  
 IS Development
Methodologies

“Comprehensive guidelines
to follow for completing
every activity in the
systems development life
cycle, including specific
models, tools and
techniques”

50  
Process- Blended Object- Rapid People- Organizatio Framework
Oriented Oriented Oriented nal-
Oriented
STRADIS Structured Booch James CommonKADS Soft-System Multiview
Methodology System Method Martin’s Methodolo-
- Gane & Analysis & RAD gy (SSM)
Sarson’s Design
Methodology Method
(SSADM)

Yourdon … OOSE Extreme ETHICS IS work and Strategic

System Programmin analysis of options
Method (YSM) g (XP) changes developmen
(ISAC) t and
analysis
(SODA)
Jackson OMT Web IS KADS Process Capability
System developmen Innovation Maturity
Development t (PI) Model
(JSD) methodolog (CMM)
y (WISDM)

… Unified … … Project in …
Approach controlled
Methodolo- environmen
gy ts (PRINCE)

Rational …
Unified
Process

… 51  
 Two General
Approaches to IS
Development
Traditional Object-
Approach Oriented
Approach

Structured
Approach

“…All system developers should be familiar with two very

general approaches (structured, OO) to system
development, because they form the basis of virtually all
methodologies…” 52  
The Main Components
of Methodology (MCM)

Techniques Tools

METHODOLOGY

Models

53  
 MCM>Techniques,
Models, Tools (TMT)

§  Techniques is a collection of guidelines

that help an analyst complete a system
development.
§  Model is a representation of some
important aspect of the real world
§  Tool is software tool that helps create
models or other components required
in the project
54  
 MCM>TMT>Samples

1.  Flowchart   1.  Strategic  Planning   1.  CASE  

2.  Data  Flow  Diagram   2.  User  interviewing   2.  Drawing/graphic  
(DFD)   techniques   applicaOons  
3.  EnOty-­‐RelaOonship   3.  Data-­‐Modeling   3.  Reverse-­‐engineering  
Diagram  (ERD)   techniques   tool  
4.  Structure  Chart   4.  Sodware-­‐tesOng   4.  Code  generator  tool  
techniques  
5.  Class  diagram   5.  Database  management  
5.  Project  Mgt  techniques   applicaOon  
6.  Sequence  diagram  
6.  Structured  analysis  &   6.  Word  processor  
design  techniques  

55  
 Structured & O-O
Methodologies

Structured O-Oriented
Methodologies Methodologies
1.  STRADIS 1.  Booch
2.  SSADM 2.  OMT
3.  JSD 3.  OOSE
4.  YSM 4.  Unified Approach
5.  More… 5.  Rational Unified
Process
6.  More…

56  
 PROCESS 1
?????
Problem
PROCESS 4 PROCESS 2

“Structured” PROCESS 3

OBJECT 1

OBJECT 4 OBJECT 2

“OO” OBJECT 3

57  
 Approaches  to  Structured  Analysis  and  
Design  and  to  the  Systems  Development  
Life  Cycle  
•  TradiOonal  systems  development  life  cycle  
•  CASE  systems  development  life  cycle    
•  Object-­‐Oriented  Systems  Analysis  and  Design  

58  
 Case  Tools  
•  CASE  tools  are  producOvity  tools  for  systems  
analysts  that  have  been  created  explicitly  to  
improve  their  rouOne  work  through  the  use  of  
automated  support  
•  Reasons  for  using  CASE  tools  
–  Increasing  Analyst  ProducOvity  
–  Improving  Analyst-­‐User  CommunicaOon  
–  IntegraOng  Life  Cycle  AcOviOes  
–  Accurately  Assessing  Maintenance  Changes  

59  
 Case  Tool  Classifica-ons  
•  Upper  CASE  tools  perform  analysis  and  
design  (mainly  for  analyst  &  designers)  
•  Lower  CASE  tools  generate  programs  
from  CASE  design  (use  by  programmers)  
•  Integrated  CASE  tools  perform  both  upper  
and  lower  CASE  funcOons  

60  
 Upper  CASE  Tools  
•  Create  and  modify  the  system  design  
•  Help  in  modeling  organizaOonal  
requirements  and  defining  system  
boundaries  
•  Can  also  support  prototyping  of  screen  
and  report  designs  

61  
 Lower  CASE  Tools  
•  Lower  CASE  tools  generate  computer  
source  code  from  the  CASE  design  
•  Source  code  is  usually  generated  in  
several  languages  

62  
Tradi-onal  versus  CASE  systems  
development  life  cycle  

63  
 Object-­‐Oriented  Systems  
Analysis  and  Design  
•  Alternate  approach  to  the  structured  approach  of  the  
SDLC  that  is  intended  to  facilitate  the  development  of  
systems  that  must  change  rapidly  in  response  to  dynamic  
business  environments  
•  Analysis  is  performed  on  a  small  part  of  the  system  
followed  by  design  and  implementaOon.  The  cycle  repeats  
with  analysis,  design  and  implementaOon  of  the  next  part  
and  this  repeats  unOl  the  project  is  complete  

1-­‐64  
 Alternate  Approaches  to  Structured  Analysis  
and  Design  and  to  the  Systems  Development  
Life  Cycle  
•  Agile  approach  
•  Prototyping  
•  ETHICS  
•  Project  champion  
•  Sod  Systems  Methodology  
•  MulOview  

1-­‐65  
 Summary  
•  InformaOon  is  a  key  resource  
•  Systems  analysts  deal  with  many  types  of  informaOon  
systems  
•  IntegraOon  of  tradiOonal  systems  with  new  technologies  
•  Roles  and  qualiOes  of  the  systems  analyst  
•  The  systems  Development  Life  Cycle  
•  CASE  tools  
•  AlternaOves  to  structured  analysis  and  design  and  to  the  
SDLC  

1-­‐66  
OVERALL  PICTURE  OF  SYSTEMS  
ANALYSIS  &  DESIGN  

67  
SYS. ANALYSIS
Information
Gathering

Analyze Project Mgt

§ WFD, AD,
Proces Information etc
s
Model
§ Logical DFD
s & new
current
system
Data SYS. PLANNING
§  Decision Model
table, decision
trees, etc
Feasibilit
Process Design (Convert Probl. y
DFD to Str. Chart Definition
Report – first
Output Design SYS.
mile stone
Program Design IMPLEMENTATION
Input Design final output
Database Design (present the
SYS. DESIGN system)

Design spec Report 2nd 68  

milestone
 References  
•  Kendall,  K.E.  &  Kendall,  J.E.,  2014.  System  
Analysis  and  Design.  9th  Ed.  Essex:Pearson.    

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