Some SDLC models

★ The Linear model (Waterfall)

- Separate and distinct phases of specification and development

- All activities in linear fashion

- Next phase starts only when first one is complete

* Evolutionary development

- Specification and development are interleaved (Spiral,incremental,prototype based,Rapid Application development)

- Incremental Model (Waterfall in iteration)

- RAD(Rapid Application Development) - Focus is on developing quality product in less time

- Spiral Model - We start from smaller module and keeps on building it like a spiral. It is also called Component based development.

★ Formal systems development

- A mathematical system model is formally transformed to an implementation

★ Agile Methods

- Inducing flexibility into development

★ Reuse-based development

- The system is assembled from existing components