Agile versus Waterfall Methodology: Which is Best for your Project?
Which is better, waterfall or agile approach, in a given situation?
The waterfall method is most appropriate when there is a very clear picture of the end product, when you clearly want to thwart the ability for stakeholders to make changes, and when the project definition versus speed is most important to success. Agile is better when speed is of utmost importance, requirements may change or evolve, and a degree of flexibility regarding the end product is needed.
There is an additional challenge, however, with the long lead times inherent in the waterfall approach. The problem is that managing scope over time is much more difficult than managing it within short, well-defined timeframes. Longer timeframes mean competing priorities and a changing landscape - because things change over time!
What I am getting at is that sometimes a combination of politics and management can nudge the project scope in different directions. Authority can destabilize or change, and that moment of agreement to move forward on something is fleeting. The types of things that can get in the way when you have long timeframes include somebody's pet project, an idea for a demo with a purpose a bit outside the scope of the project, etc.
It is for this reason that I think an agile approach should be considered at least for portions of all projects. It can keep the project in line with its true purpose and more easily deflect distractions. Plus, the agile and waterfall methods are not mutually exclusive; a modified approach that incorporates the appropriate elements from each can be the most effective way forward.