Waterfall vs Agile: sequential or iterative approach?
In project management, regardless of your sector of activity, the type and size of the project you are working on, it is essential to choose an appropriate methodology in order to promote the success of the project management.
Indeed, opting for a unique and well-defined method allows all project actors to evolve within a structured framework and to follow precise instructions in order to achieve the objectives set on time. By adopting the appropriate methodology, the project team will demonstrate organization, efficiency and speed.
To help you choose, let's compare the two most used approaches in project management: the traditional Waterfall methodology and the more recent Agile approach.
Waterfall: the classic method
Also called “cascading”, the Waterfall methodology has been known since the 1970s. It is a linear and sequential method where all the steps are dependent on each other. Thus, a task can only start when the previous one is complete and validated. Like water flowing down a waterfall, there is no turning back is possible (except in case of major problems).
With this traditional method, the client and the project team define and plan the entire project in specifications from the start. The client clearly indicates his needs, expectations and requirements to the project manager and his team. Then, they get to work by completing the project sequence after sequence until the final delivery to the customer. During each sequence, a feature is developed and then validated. The project team only moves on to the next stage if the previous one is successfully completed.
Strict and rigid, the Waterfall methodology is perfectly suited to small projects. It makes it possible to produce a complete finished product that complies with the specifications, and to respect a given budget.
Agile: a more flexible approach
More recent, the philosophy Agile was created in 2001 by seventeen software development experts to fight against the high failure rate of IT projects. Today, the Agile method is becoming more and more popular.
Unlike the Waterfall methodology, the Agile approach is iterative and works in short cycles with intermediate deliveries in order to be able to adapt to change. The project is divided into stages called iterations that last no more than a few weeks. We assume that the needs and requirements of the customer may change during the project. It is therefore essential to involve the customer in the implementation of the project and to communicate regularly with him in order to properly meet his expectations.
Highly flexible, the Agile method is suitable for more complex projects and makes it possible to better control the budget and improve the productivity of the project team.
The pros and cons of each methodology
Discover the strengths and weaknesses of these two approaches to choose the one that best fits the management of your project.
Waterfall
Benefits/Disadvantages A structured, simple and easy to implement method that adapts very well to small projects for which the quality of the final result is essential. The Waterfall methodology is not suitable for larger and/or complex projects. With detailed specifications and precise planning from the start, Waterfall provides a precise idea of the budget necessary to carry out the project and the delivery date. The rigidity of the method does not make it possible to take into account the unexpected and the evolution of the client's needs, which can result in a project that no longer corresponds to the current market and does not satisfy the client. Once the specifications are defined, the presence of the customer is not essential to the realization of the project, which is an asset for customers who are not very available. In the event of a change, the changes can only be made after delivery, and therefore risk being very expensive because all the sequences of the project are potentially impacted.
Agile
Benefits/Disadvantages The major advantage of the Agile approach is its great flexibility. The project team can react immediately to unexpected events and make changes quickly. It is therefore adapted to sectors that are changing rapidly. The ease of taking into account changing needs and making changes can lead to the production of a final product that is completely different from what was originally planned. The customer is at the heart of the project. The team communicates and works jointly with him on a daily basis to ensure that the project meets his needs and requirements. The Agile approach works well if the client plays the game and collaborates regularly with the project team. On the other hand, if the customer is not available or does not want to invest fully in carrying out the project, this may be a problem. With this method, you have better control of your budget. At the end of each iteration, the project team and the client know the status of the budget. They can therefore decide whether or not to continue the project depending on the budget that is still available. While changes are easy to make, each change requires new tests and possible errors to be corrected. All of this is likely to prolong iteration and push back deadlines. It also requires more work from the project team, which was not necessarily planned at the start of the project.
To conclude
While the Agile method is more flexible, the Waterfall methodology is more structured. Each has its strengths and weaknesses. The choice will therefore depend on your team, the nature of your project, the market and the involvement of the customer.
For a highly structured project on a stable market, opt for the Waterfall approach. On the other hand, a project with fairly vague outlines in a constantly evolving market must be carried out according to Agile principles. However, be aware that it is possible to combine the two approaches to create a hybrid method.
Bonus : find out if the Agile method suits your project.
