S6ftware process model

1. Spiral Model
SOFTWARE DEVELOPMENT LIFE CYCLE (SDLC)
Bilal Bashir, Roll no: 09
Syed Shahzaib Sohail, Roll no: 19
Khuram Junaid, Roll no: 22

2. Antiquity
 Spiral Model was first described by "Barry Boehm"
in his 1986 paper "A Spiral Model of Software
Development and Enhancement".
 Boehm describes the spiral model as a "Process
Model Generator".
 Later in 1988, Boehm published a similar paper to
wider audience.

3. Spiral Model?
 Spiral model is a SDLC model used in
Information Technology.
 It combines the features of prototyping and
waterfall model.
 It is best suitable for complex, expensive and
large projects.

4. Spiral Model
 The Spiral Model
involves five phases.
 Each part of the project is
done through a spiral
(Iteration).

5. Spiral Model
Communication:
Tasks required to establish effective
communication between developer and customer.
Planning:
Tasks required to define resources, timelines and
other project related information.
Modeling:
Tasks required in building one or more
representations of the application.

6. Spiral Model
Construction and Release:
Tasks required to construct, test, install.
Deployment:
Tasks required to deliver the software, getting
feedbacks etc.

7. Spiral Model
 Based on a customer evaluation, the
development process enters into next iteration.
 Following the feedback suggested by the
customer.
 The process of iteration along the spiral
continues throughout the life of the software.

8. Advantages
 Provides early indication of risks, without much
cost.
 Users the systems early.
 Early and frequent feedback from users.
 Emphasize flexibility and extensibility.
 High quality product can be produced.

9. Disadvantages
 Time spent for evaluating risks too large for small or
low-risk projects.
 Time spent for planning, resetting objectives, doing risk
analysis and prototyping may be unnecessary.
 Risk assessment expertise required.
 Spiral may continue indefinitely.
 In fixed budget development, spiral model can be a
problem.

10. When To Use?
 When costs and risk evaluation is important.
 From medium to high risk projects.
 Long term project commitment.
 Users are unsure of their needs.