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WATERFALL is a traditional project management methodology. It is also called the “cascade” or “flow” model, due to the fact that its proposed sequence of phases resembles a waterfall. The most obvious way to make your project more manageable is to break down its implementation processes into consecutive stages. Such linear structure is a foundation of traditional project management. This approach does not imply a return to the previous stages upon their termination and adoption, or making changes to the project requirements. This project management methodology involves splitting a project into a series of sequential assignments, with a clear estimated objectives and deadlines. Project members perform tasks in due course, completing each assignment before proceeding to the next one. The stages in the “waterfall” model as applied to IT software development projects, are the following:

• Requirement analysis

• Design

• Implementation

• Integration

• Verification

• Installation

• Maintenance

Stages of Waterfall model

In this case, the developer cannot proceed to the next stage without completing the previous one. First, the requirements are completely defined, resulting in a list of software requirements. The next stage is design aimed to create the documents with detailed description of the method and plan for implementing these requirements for programmers. After the design is completed, the programmers carry out the project. The next stage deals with the integration of individual components developed by various programming teams. After the implementation and integration are completed, the product is tested and debugged. At this stage, all shortcomings that occurred during the previous development stages are eliminated. After that, the software product is implemented and maintained – introducing new functionality and eliminating errors.

The strengths of the classic project management are the requirement for the customer or company leadership to determine what they want to get at the first stage of the project. Early inclusion brings some stability to the project, while planning streamlines the implementation of the project. Besides, this approach involves monitoring indicators and testing, which is absolutely necessary for real projects. Potentially, the classical approach allows avoiding stress since there is spare time at each stage, reserved for any complications and risks occurring. Moreover, correct planning stage allows the project manager to know what resources are available, even if this assessment is not always accurate. The main benefit is an ability to estimate the implementing cost of the solution in advance and monitor the state at all stages of the project management life cycle.

The weaknesses of the classic project management are the intolerance for change. If your project is not restrained in resources and time, and the project content has been modified, you should better look at other project management systems. Moreover, in real IT projects it is quite difficult to formulate detailed requirements for the final project at the initial stage.