The document discusses the spiral model, a systems development method that combines prototyping and the waterfall model. It is favored for large, complex projects. The spiral model involves iterating through four phases - planning, risk analysis, engineering, and evaluation. A case study is presented of Galaxy Inc., which used the spiral model to develop a satellite communication system. Key challenges included risks, lack of experience, and complex requirements. The spiral model helped Galaxy Inc. address risks, gather expertise, and maintain transparency through iterative development cycles.

1. Challenges with new
project?

2. What is Spiral Model ?
 The Spiral Development ( or Lifecycle) Model is a systems
development method used in information technology.
 It combines the features of the prototyping model and
the waterfall model.
 It is favored for large, expensive, and complicated
models.

4. Spiral quadrant : 1
 Objectives: functionality, performance, hardware/software
interface, critical success factors, etc.
 Alternatives: build, reuse, buy, sub-contract, etc.
 Constraints: cost, schedule, interface, etc.

5. Spiral quadrant : 2
 Study alternatives relative to objectives and constraints
 Identify risks (lack of experience, new technology, tight
schedules, poor process, etc.
 Resolve risks (evaluate if money could be lost by continuing
system development

6. Spiral quadrant : 3
 Typical activities:
 Create a design
 Review design
 Develop code
 Inspect code
 Test product

7. Spiral quadrant : 4
 Typical activities:
 Develop project plan
 Develop configuration management plan
 Develop a test plan
 Develop an installation plan

8. Why are we discussing spiral Model?
 Case Study
 Galaxy Inc. tried to develop a satellite based communication between
mobile handsets.
 The system would work through six dozen of satellites.
 Communication also possible in areas like arctic and Antarctica.
 Any call can be made in the satellite range.

9. When to use spiral model
 Long-term project commitment unwise because of potential
changes to economic priorities.
 Users are unsure of their needs.
 Requirements are complex.
 New product line .
 Significant changes are expected (research and exploration).

10. Challenges ahead Galaxy Inc.
 Risks were enormous.
 No publishes material or experienced staff.
 Risks will be identified once the projects kicks off.
 Several million of code had to be written.

11. What Galaxy Inc. did?
 They had to hire staff that is experienced enough for the project.
 Had to gather the matter and work on the proceedings.
 The transparencies were maintained in respect of the views and
opinions of people.
 They decided to run parallel to SPIRAL model.

12. When to use spiral model
 Long-term project commitment unwise because of potential
changes to economic priorities.
 Users are unsure of their needs.
 Requirements are complex.
 New product line .
 Significant changes are expected (research and exploration).

13. Advantages (strengths)
 Estimates of the budget and schedule become more realistic as
work progresses because of the questions that have been raised
 Easier to cope with the changes inherent to software development
 Software engineers can start working on the project earlier rather
than wading through a lengthy early design process.

14. Disadvantages (weaknesses)
 Time spent for evaluating risks too large for small or low-risk
projects.
 Time spent planning, resetting objectives, doing risk analysis and
prototyping may be excessive.
 The model is complex.
 Risk assessment expertise is required.