Waterfall Software Development

Waterfall software development is the most primitive methodology of software development. It is a one which comprises of a sequence of phases one after another. Imagine the Niagara Falls. Waterfall methodology works in the same way hence the name. It basically advocates a step by step approach which means that one step should be completed before the next one is begun. It is also known sometimes as the linear sequential model of software development.

Waterfall software development model originated from a similar model that was used by the manufacturing and construction industries. It was developed at a time when the software industry decided it needed some kind of formal process of software development. Since there was no formal software development life cycle model it was decided to take the one currently in use in the manufacturing industry and use it in the software development industry.

The Phases of Waterfall Development

The initial waterfall software development model had five major phases however the number increased when it was modified in subsequent versions. The five major phases are:

1.0 Requirement Phase

This phase is marked by defining the problems or reasons which has lead to the particular software needing to be developed. All the requirements (business requirements documentation (BRD) and project management requirements) are stated and specified along with the constraints.

2.0 Design Phase

The main concerns at this phase are data structure, architecture, details of algorithms and interface representation. The software requirements specification (SRS) will detail most of this information. This phase also includes the decision on hardware. Hence the developer is able to understand the relationship among the three components i.e. hardware, software and the interfaces.

3.0 Implementation Phase

This phase of waterfall software development includes the actual coding of the software components and their integration.

4.0 Verification Phase

This is obviously one of the stages of software testing and involves testing the software against requirements and use cases. It also includes fixing any defects found as determined by the software testing life cycle.

5.0 Maintenance Phase

This includes making small changes in the software to meet the changing requirements of the customer. It would also include improving on errors that went undetected earlier and thereby improving on the overall efficiency of the software.

Waterfall Software Development - Tip

Waterfall methodology still has a part to play in big manufacturing industries where requirements are set and development timeframes are long. However utilising it in the fast moving internet area for example would be nothing short of an absolute disaster in terms of accurately estimating project costs and the project scope statement.