The Spiral Model is a software development process combining elements of both waterfall and prototyping models. It consists of four phases - Planning, Risk Analysis, Engineering, and Evaluation - that are repeated in iterations or "spirals" throughout the project. Each spiral phase begins with designing the goals for that phase and ends with the client reviewing the progress. The Spiral Model emphasizes risk analysis and is well-suited for large, complex projects where requirements are not fully known.

1. Spiral Model
Presented by – YASH PRASHANT PUROHIT
20MIS0364
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2. Contents
• What is Spiral Model?
• Phases
• When to use Spiral Model?
• Advantages and Disadvantages
• Conclusion
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3. What is spiral model?
• Spiral model is one of the most important Software Development
Life Cycle models, which provides support for Risk Handling.
• Spiral Model is a combination of a waterfall model and prototype
model.
• Each phase in spiral model begins with a design goal and ends with
the client reviewing the progress.
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4. • The spiral model was first mentioned by Barry Boehm in his 1986 paper.
• The spiral model is similar to the incremental model, with more emphasis
placed on risk analysis.
• The spiral model has four phases: Planning, Risk Analysis, Engineering
and Evaluation.
• Software project repeatedly passes through these four phases in iterations
(called Spirals).
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5. Four Phases of Spiral model
• Planning
• Risk Analysis
• Engineering
• Evolution
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6. Phases
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7. Planning
• This phase starts with gathering the
business requirements in the baseline
spiral.
• In this phase, Software Analyst
communicate with the clients and the
necessary requirements such as
Business requirements and System
requirements are gathered.
• Planning includes estimating the cost,
schedule and resources for the iteration.
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8. Risk Analysis
• In this phase analyst assume all
the possible risks that could be
occurred during future
development.
• A prototype is produced at the end
of the risk analysis phase.
• If any risk is found during the risk
analysis then alternate solutions
are suggested and implemented.
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9. Engineering
• In this phase software is
developed, along with
testing at the end of the
phase.
• Hence this phase includes
testing, coding and
deploying software at the
customer site.
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10. Evaluation
• In this phase, Customers
evaluate the so far
developed version of the
software.
• In the end, planning for the
next phase is started.
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11. When to use spiral model?
• When project is large
• Where the software needs continuous risk evaluation.
• When risk and costs evaluation is important
• For medium to high-risk projects
• When requirements are unclear and complex.
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12. Advantages of Spiral model
• Additional functionality or changes can be done at a later stage.
• Cost estimation becomes easy as the prototype building is done in
small fragments.
• Continuous or repeated development helps in risk management.
• Development is fast and features are added in a systematic way.
• There is always a space for customer feedback and the changes are
implemented faster.
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13. Disadvantages of Spiral model
• Risk of not meeting the schedule or budget.
• It works best for large projects only also demands risk
assessment expertise.
• For its smooth operation spiral model protocol needs to be
followed strictly.
• Documentation is more as it has intermediate phases.
• It is not advisable for smaller project, it might cost them a lot.
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14. Conclusion
• Each spiral can be termed as a loop and each loop is a separate
development process in a spiral model.
• This model is very good to use for larger projects where you can
develop and deliver smaller prototypes and can enhance it to make
the larger software.
• The implementation of this model requires experienced resources as
risk analysis is a very integral part of this model and risk analysis
requires expertise and as a result this model becomes costly.
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15. Thank You!
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