Other SDLC Models

Waterfall with Prototyping
Prototyping to analysis and design phases

Preview and validation of User Interface by customer.

Preview and validation of complex workflows by customer.

Technical risks mitigation etc. Feasibility. Biggest Risks

Correctness and completeness of earlier phases is a prerequisite of each phase.

Risks related to complex functionalities and large size of projects.

Might not handle all scenarios.

Evolutionary Prototyping Methodology.

1. Here the system concept evolves during the project
   • Develop a prototype
   • Show it to customer. Get their feedback.
   • Refine the prototype. Repeat till prototype is “good”.
   • Complete any pending work and release the product.
2. Appropriate when
   • Rapidly changing requirements
   • Customer can not commit to a set of requirements. Poor understanding of the application area (by customer or developer).
   • Poor understanding of technology, architecture or algorithms.
3. Problems
   • Cant predict efforts, size, costs.
   • Demands on good engineering, to ensure sustaining every iteration.

Rapid Application Development

1. Modified waterfall model that emphasizes an extremely short development life cycle
   • Methodology driven by tools which achieve rapid development
     • Joint Requirements Planning
     • Joint Application Development
     • Construction
     • Cutover
   • Costs of rework is very less. So, design and testing phases and shortened
2. Appropriate if the requirements can be realized using the tools
   • CASE tools (such as VB, Borland Delphi, PowerBuilder etc.)

Product Lifecycle Models

1. Modification of iterative model
   • Multiple cycles of development, adding newer features in every cycle.
   • Requirements driven by the market, not by specific customers.
     • Influenced by competing products.
     • Present customer base as well as targeted customers.
2. Each cycle builds on earlier cycle’s work products
   • Stable architecture and standard development practices.
   • Requirements gathering and analysis is more tedious.
   • HLD and architecture inherited from earlier cycles.
   • DD & CUT combined to one stage.
   • System testing is elaborate.
   • Customer testing is more tedious: alpha and beta.
3. Biggest Risks and Challenges
   • Conflicting requirements from diverse customer base.
   • Need to rapidly change to adapt to changing market pressures.