Before you start any project, there is preparation work to be done, requirements to gather, solutions to evaluate, estimates to present. And once youíve completed the preliminary step, then itís time to decide how youíre going to execute your project.
A common practice to start at the end i.e. your end product or project completion and work backwards, identifying the key landmarks that can act as progress indicators as well as being measurable aspects of the project.
These landmarks will mark your deliverables, and thus your project phases. However, some requirements have to be regularly assessed throughout the life of the project, and you might set a different schedule for their review. Time-critical projects or projects that have a zero margin for error need to be continuously reevaluated based on respective criteria. On the other hand, it might be more efficient to let phases overlap, as each phase involves some independent preparatory work that can be done beforehand. Then, as each phase nears completion, the development process can be jumped by using the results from one phase in the next without waiting for a formal transition. Parallel project development is a powerful tool that should be used only when the team is experienced and well-prepared.
In the end, phasing your projects is a decision thatís based on past experience, project complexity and the preparation done in the preliminary phase.