Difference between Waterfall and Incremental Model

Different models have been purposed by project managers for the development of software. The choice is made from the purposed model according to the requirements of the software. Different models purposed which include: waterfall model and Incremental model. The major cause due to which most projects failed is technical issue. The technical risk involves the choice of model for development. If the choice of model is very complicated decision and should be made with great concern. Otherwise the project will doom to failure.

Waterfall Model

Waterfall include following steps: Requirements, design, implementation, testing and integration and maintenance. Waterfall model cannot be tracked back. It is used for large projects. It was purposed by computer scientist Winston Walker Royce in 1970.

Incremental Model

Incremental model consists of following steps: Requirement, Specification, Architectural design, Implementation, Maintenance and retirement. It is combination of undeviating and iterative model. It can straightforwardly accept change. It was purposed by IEEE in 2003 due to defects in waterfall model. As waterfall is not suitable for all models

Waterfall and Incremental Model

User involvement:

In waterfall model user involvement is not much. User is involved in one stage of waterfall model that is requirement.

In incremental model client is involved at every stage. After development of every module it is given to the user.

Supply:

The software is delivered to the user only after all the stages of life cycle is completed.

Every increment is delivered to the user and after the approval of user the developer will move towards the next module.

Variability:

Waterfall model does not support changeability. It cannot be traced back.

Changes can be made according to the requirements. The software made using incremental approach can easily be modified and can survive for more years.

Credentials:

Documentation is given at every stage of waterfall model. The main focus is documentation as end product.

In incremental model the major focus is not documentation but a user satisfied product.

Manpower:

More manpower is required for development.

In incremental model less staff is required as compared to waterfall model.

Time limitation:

In waterfall operational quality portion is delivered after months.

In incremental the operational product is given to the user within weeks.

Project size:

Waterfall model is not suited for small projects. It is only suited for large projects.

Incremental model can be suited for small projects.

Conclusion

The choice of project is made according to the requirements. Whenever the concern is documentation we will make choice of waterfall model. And when our concern is making software that readily accepts change we will choose incremental model.