Waterfall vs. Agile in Project Management

There are different models that can be used to provide a workflow for managing even the most complex of projects. The waterfall and agile models, for example, are two contenders in the software development arena. Each model has strengths and weaknesses, which makes it important that project managers choose appropriately based on the specific project at hand.

The Waterfall Method

This method, frequently used in software development, involves a very systematic, linear methodology that guides a project forward from one stage to the next in a downward, waterfall-like manner. A typical project being managed using the waterfall method might involve such distinct phases as:

• Study, analysis and definition of the project and its desired goal – This is the phase during which brainstorming takes place and the purpose and scope of the product is fully defined.
• Basic design of the software – This phase involves formulating the fundamental design of the software on paper.
• Technical and detailed design – Once a basic design is approved, a more elaborate technical design phase begins. This is where functions are mapped out and engineering units are placed.
• Construction and implementation of the software – This is when the actual coding work comes into play as the program is written.
• Testing – This phase involves testing the resulting program for functionality while seeking out errors that may need correcting.
• Integration – This phase brings the new software package into use after it has been successfully tested.
• Management and maintenance – The final phase is basic upkeep of the program to ensure desired performance continues.

By its very design, the waterfall model is rigid. Once a project moves from one phase to the next, going back and correcting errors or making adjustments can be difficult. If major problems are discovered within a certain phase, the entire process might need to be restarted.

The Agile Method

As its name implies, the agile method can help provide more flexibility during project development. This method does not require a rigid, sequential framework. Instead, it begins with a basic project design, but no outlined, predetermined course to follow. In this model, designers work on small modules in sprints with project priorities being discussed and tested before moving forward to the next sprint.

Agile project management is often set up with three basic roles: the product owner, the scrum master and the team of developers. The owner is responsible for defining the project and the purposes it must serve to meet business needs. The scrum master serves as the coach, ensuring that progress is made and goals are met. The team itself is responsible for determining how to meet goals established by the product owner. Testing occurs frequently within this highly collaborative model, ensuring bugs are spotted and corrected early and that client satisfaction is attained before the next sprint begins.

Common Themes

While the waterfall and agile methods are different by design, they do offer some similarities. Both forms of project management are designed to place a framework of structure over the development of a new product. In both cases, a project owner defines the scope of the product while the team seeks to bring realization of the goal to fruition. Both methods can result in well-managed projects and highly-tailored products meant to meet the needs of the project owner and the goal assigned at the start, as in the case of the waterfall method, or defined as the project moves forward, as is often the case with the agile method.

Differences That Distinguish the Methods

While both the agile and waterfall methods result in a final product, the manner in which the results are attained tends to be quite different.

When the waterfall method is employed, the project plan defines the entire process. This method tends to lack flexibility and requires meticulous work in every phase to ensure that mistakes are not made. The method is linear by design and calls for careful execution each step of the way. However, problems with waterfall can arise when feedback and testing are deferred until the very end phases, when making corrections can be difficult. This approach, however, may make it easier to determine budgets and set deadlines.

In the waterfall method, the plan-driven process isn’t necessarily dependent on a single person or group of people to reach completion. If a designer leaves, for example, a new one can easily step in and review back to detailed plan notes to be brought up to speed.

The agile method delivers flexibility by design, but the process can be hard to predict, especially in regard to budgets and timelines. In the absence of a concrete plan, goals often remain vague and fluid, and oversight of this collaboration-intensive process can be problematic. Development in this model tends to be rather person-based, which means removal of a team member can be problematic.

Project Impacts

Choosing the right model to use for a project often comes down to personal choice and the needs of the specific project. There is no single “best” choice, but the impact of each method can make one a stronger option for certain types of projects versus the other.

The agile method tends to work well with projects that lack a clearly defined end goal and where requirements are fluid. This approach is designed to allow frequent adjustments without the need to start completely over in the process. In addition, the ability to test at each project stage may enable a stronger chance of a successful outcome.

The waterfall approach is often well-suited for projects that are static and have very well-defined goals that are not likely to change. This method also lends itself to projects that involve little opportunity for constant feedback between the team and the client or project owner. The desired outcome is clearly stated from the start and the project moves forward from phase to phase without a strong need for collaborative interaction.

Both the waterfall and agile methods are designed to help enable a project to move forward from Point A to Point B. They each have pros and cons, but when well-managed, they can both result in the desired outcome.