4b Software Engineering - Lecture#4 (B)
4b Software Engineering - Lecture#4 (B)
4b Software Engineering - Lecture#4 (B)
LECTURE 4(B)
INSTRUCTOR: ANAM ASHRAF
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OUTLINE
Prototyping Model
Spiral Model
Win-win Spiral Model
V-Model
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PROTOTYPING MODEL
Prototyping Model assists the software engineer and the customer to
better understand what is to be built when requirements are fuzzy.
Often customer defines a set of general objectives for software, but
does not identify detailed input, processing or output requirements. In
these situations a prototyping paradigm may offer the best approach.
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WHERE IS PROTOTYPE MODEL USED?
Modeling And • The quick design focuses on a representation of the customer/user (e.g,
Quick Design input approaches and output formats).
For larger, more critical projects, each task region contains more
work tasks that are defined to achieve a higher level of
formality.
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• Realistic to the development of large-scale
systems
Advantages • Iteratively reduces risk
• Allows repeated use of the prototyping
approach
• Customers may not like it, fearing lack of
control
• Demands risk assessment expertise and
Problems relies on this expertise for success.
• If a major risk is not uncovered and
managed, problems will undoubtedly occur.
• It is very lengthy process.
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WIN WIN SPIRAL MODEL
The objective of this model is to elicit project
requirements from the customer.
The best negotiations strive for a “win-win”
result.
That is, the customer wins by getting the
system or product that satisfies the majority of
the customer’s needs and the developer wins
by working to realistic and achievable budgets
and deadlines. 11
V MODEL
It means verification and validation .
• Just like WATER FALL model, The life
cycle of the V model is a sequential
path of the execution of the process.
• Each phase must be completed before
the next phase begins.
• The testing of the product is planned
in parallel with corresponding phase of
development.
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WHEN TO USE V-MODEL?
It should be used for small to medium size projects
where requirements are clearly defined.
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PHASES OF V-MODEL
Requirements
High-Level
Design (HLD)
Low-Level
Design (LLD)
Implementation
Coding 14
Requirements In this model the requirements are gathered before its development and a system test plan
is created. The plan test focuses on meeting the functionality specified in the requirements
gathering.
High-Level It focuses on system architecture and design. It provide overview of the solution, platform
system, product and services/process. An integrated test plan is created here as well as in
Design order to test the pieces of the software system ability to work together.
Low-Level Here the actual software components of software are design . It defines the actual logic for
each and every component of the system. Component test are created in this phase as well.
Design
Coding It is that phase where all the coding take place. Once coding is complete, the path of
execution up the right side of the V where the test plans developed earlier are now put to
use.
Implementation This is at the bottom of the V-model. Module design is converted into code by developer.
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• Simple and easy to use.
Testing activities like planning, test design
Advantage happens well before coding.
• This saves a lot of time.
s • Avoids the down word flow of the defects.
• Works well for small projects where
requirements are easily understood.
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QUESTIONS?
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