Agile and Waterfall Methodologies

Agile and waterfall are two distinctive methodologies of processes to complete projects or work items. Agile is an iterative methodology that incorporates a cyclic and collaborative process. Waterfall is a sequential methodology that can also be collaborative, but tasks are generally handled in a more linear process.

Following the agile methodology, your project will move through a series of cycles throughout the lifetime of the project. The development phase, review, feedback, and then approval of the work item – either yes or no. If yes, implement and complete the task. If no, record and make any necessary changes, track and adjust the backlog or prioritization to reflect the newly acquired knowledge, and then move onto the next task or sprint.

Following the waterfall methodology is a simpler process of moving tasks through the phases of defining requirements, designing the implementation, implementing the work item, verification of implementation and quality assurance, and then maintenance of the feature in the end.

How to choose?

Agile makes sense where a project is based on incremental progress, complex deliverables or consists of multiple, not always sequential timelines. Projects that require cohesive and collaborative but cross-functional teams to deliver will need to take an Agile approach.
If processes or roles are unclear it makes room for figuring it out as the project goes along. It also allows for involving the project client at any stage along the way. Products that are developed in stages, updates or versions are particularly suited to Agile.

Waterfall is usually more suited to less complex projects or those that have well defined requirements, processes and roles for team members. Single delivery timeframes with lots of detail and an expectation that very little is likely to change along the way are ideal.
Waterfall also works well when the client is not required to be heavily involved beyond the initial brief and final delivery. From a management point of view, Waterfall can often make sense for fixed-price or contract dependent projects in order to lessen the risk of budget or delivery over-runs.