Transcript Slide 1

Models of Software Development Life Cycle (SDLC)
• The objective of this section is to introduce you the idea
of software process – a coherent set of activities for
software production. When you have read this section
you will:
• understand the concept of a software process and a software process
model;
• understand a number of different software process models such as
waterfall, spiral and iterative models.
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What is a SDLC Model?
• An SDLC model breaks down the development process
into a sequence of phases or stages.
• The end of a phase is called a milestone of the project. The
outcome of the phase is delivered to the customer as a
milestone of the project.
• Breaking down the development process makes it easier to
manage.
• Each phase can be performed in various ways.
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Why use SDLC Model?
In the earlier days, projects were developed without proper
specification or any attempt in design and were just built, and
reworked as many times needed to satisfy the customer.
This is not possible for complex projects since
• There is no control on quality assurance.
• There is no risk analysis.
• There is no estimation of time and cost of the project.
• There is no proper plan.
Hence,
• The project may lead to a huge financial loss for both the customer
as well as the developer.
• The project may fail.
• The project may not be delivered in time with the satisfaction of the
customer.
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1. Waterfall Model
• In the waterfall model, software activities proceed
logically through a sequence of steps. Each step bases its
work on the activities of the previous step. The design
phase logically follows the requirements phase, the
implementation phase follows the design phase, and so on.
• Waterfall model is document driven. In principle, the
result of each phase is one or more documents which are
approved (“sign-off”). The next phase should not start
until the current phase is completed.
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Workflow of Waterfall Model
Requirement
Changed Requirements verify
Verify
Specification
Verify
Planning
Verify
Design
Verify
Implementation
Testing
Integration
Development
Testing
Deployment and Maintenance
Maintenance
Retirement
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Quiz
1.
The planning of the project is done by:
A.
B.
C.
D.
The programmer
The system analyst
The system study team
The project manager
2. During the Specification mode, the requirements are properly
documented and the document is called _________.
3. The waterfall model is
1. Document-driven.
2. Risk-driven
3. Prototype-driven
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