Application Development and Integration Life Cycle

1. waterfall Lifecycle

This model supports large and complex projects in which the requirements are well defined. It adopts sequential approach from requirements analysis through design, construction, testing and application deployment.

2. V Lifecycle

 

Suitable for projects with high requirements on system reliability. Stress testing.

This model supports new product development or large enhancement projects when the size and complexity of the system is large enough to have a multilayered design. adopt this model when the requirements are well understood, complete, and stable and the Technology & architecture of the solution is clear and visible.

Sow (UAT plan) --- requirement (System Test Plan) --- Architecture Design (integration test plan) --- low level design (unit test plan) ---- construct (V model bottom) --- unit test --- integration test --- system test --- UAT

 

2.1 feature

Concurrent phases or activities

Mandatory unit testing easy to plan emphasizes and encourages verification and validation at all phases

 

 

 

2.2 disadvantage

Does not handle iterations

Changes are expansive

More documentation and mandatory sign-off to move out of the Phase

Like waterfall model, product is not visible until the end

 

3. Staged Lifecycle

 

The architecture has been defined to allow phased low level design and implementation.

In this model, certain intermediate work products (incremental deliveries) will be delivered to the client before final delivery of the entire application.

It supports product development or large enhancement projects when the requirements are not well understood and skeptic on stability of requirements.

The staged lifecycle is best suitable for the development of new products or for executing large enhancements.

Cycle: Low Level Design --- build --- it, St, Rel,

3.1 feature

When the requirements not well understood, not complete or not stable.

When there is a need for continuous deliveries from customer side.

When allow incremental design and implementation in a number of stages.

Allow for specification changes in the subsequent release

 

3.2 disadvantage

Need careful planning

Extra overhead on multiple release

Determining stage dependencies is difficult

 

4. Iterative Lifecycle

This model supports large and complex projects with the following characteristics:

Where continuous quality check & high degree of Requirements management is needed through out the project.

Where the requirements will change considerably and the environment is not stable.

Where it is not possible to specify the requirements in enough details upfront. Where delivering on time is essential, irrespective of the functionality.

 

Cycle: envisioning --- design --- build --- test --- release & Deployment

In the previous cycle, each stage has multiple iterations.

 

 

5. Rapid applicaton development lifecycle