5. Proposed by Boehm
Couples Iterative nature of prototyping + classic life cycle
waterfall model
Potential for rapid development of increasingly more complete
version of software
Software is developed in a series of evolutionary releases.
The Spiral Model
7. Divided into set of framework activities defined by the software
engineering team
Each Framework activities represents 1 segment of a spiral
path
As evolutionary process begins the software performs activities
implied by circuit in clockwise direction
Begins at the center
Framework Activities
8. Function of each circuit:
1st circuit – development of a product specification
2nd circuit – prototype is developed(trial product)
3rd and rest – sophisticated versions of software is developed
For each pass:
Planning : Adjustment of project plan is done
Cost & schedule: Adjusted based on feedback of customer after delivery
Project manager: Adjusts number of iteration to complete software
The Process
9. Anchor point milestones – a combination of work products and
conditions that are attained along the path of the spiral are noted
for each evolutionary pass.
Circuit Representation:
First circuit – concept development project
Second circuit – new product development project
Further circuits – product enhancement projects
Contd..
10. Realistic approach of development in large scale
Developer and customer satisfaction
Enables developer to apply prototype in any stage
Stepwise approach
Direct consideration of technical risk at all step.
Advantages
11. Demands considerable risk assessment expertise
Model has not been used as widely as the linear sequential or
prototype paradigm
Disadvantages
13. Summary
Evolutionary Process Models
Spiral model
Stages
Communication
Planning
Modeling
Construction
Deployment
Anchor point milestones
Concept development project
Product enhancement project
Application: To build custom software and mobile apps which
requires enhanced versions. E.g.: windows, android, etc...
14. 1. A few years ago, Sun Microsystems, decided to develop and market StarOffice,
a set of desktop tools that would be comparable to Microsoft’s office suite of
tools but would be targeted for UNIX rather than Windows. At that time no other
major UNIX vendor had developed or was planning to develop such a product.
What process model would you use?
Stimulating Questions