Agile or Waterfall: making the right choice

 One of the first decisions we face for each of our project implementations at Segue is “Which development methodology should we use?” This is a topic that gets a lot of discussion. When it comes to methodologies there are two basic and most popular options. one is Agile and the other one is waterfall.

Waterfall Model methodology which is also known as Liner Sequential Life Cycle Model. Waterfall Model followed in the sequential order, and so project development team only moves to next phase of development or testing if the previous step completed successfully.

Agile methodology is a practice that helps continuous iteration of development and testing in the software development process. In this model, development and testing activities are concurrent, unlike the Waterfall model. This process allows more communication between customers, developers, managers, and testers.

Both of these are usable, mature methodologies. Having been involved in software development projects for a long time, here are my thoughts on the strengths and weaknesses of each.

both models have advantages of both models. Below I will provide a short description.

Waterfall model advantages: 

• This is a clear framework and one of the easiest models to manage. You get a clear understanding of your project timeline and deliverables before the project begins. The project scope is agreed upon by the development team and the clients in advance.
• It provides faster project delivery.
• The method works well for smaller size projects (with easily understandable requirements).
• Planning and designing look straightforward because developers and customers can agree on what will be delivered early in the development lifecycle.
• It offers well-documented processes and results. Every project phase is documented in detail to eliminate misunderstandings and shortcuts.
• Progress is more easily measured, as the full scope of the work is known in advance.
• It provides a shared load. Depending on the phase, every team member can focus on other aspects of their work.
• Waterfall is a hands-off approach. After the initial design and project plan is in place, there is little requirement for ongoing customer presence until the review phase.

Agile model advantages: 

• The Agile methodology is focused on the client process. It makes sure that the client is continuously involved in every stage. Customers have an opportunity to see the work being delivered and to make decisions and changes throughout development.
• Customers have a strong sense of ownership by working extensively and directly with the project team throughout the project.
• Agile development is often more user-focused. This is the result of more and frequent direction from the customer.
• It guarantees that the quality of the development is clearly maintained.
• The Agile offshore development process is completely based on incremental progress.
• Agile teams are extremely and self-organized and motivated. This provides better results for development projects.
• The clients know exactly what is complete and what is not that decreases risks in the development process.
• The deliverables are flexible. Stakeholders can set deliverables by order of importance.

Limitations of Waterfall Model:

• It is not an ideal model for a large size project
• If the requirement is not clear at the beginning, it is a less effective method.
• Very difficult to move back to makes changes in the previous phases.
• The testing process starts once development is over. Hence, it has high chances of bugs to be found later in development where they are expensive to fix.

Limitations of Agile Model

• It is not useful method for small development projects.
• It requires an expert to take important decisions in the meeting.
• Cost of implementing an agile method is little more compared to other development methodologies.
• The project can easily go off track if the project manager is not clear what outcome he/she wants.

Making the Choice Between Agile and Waterfall

Your ultimate choice between Agile vs Waterfall methodologies depends much on several factors. Agile and Waterfall are very different and it will not always be possible to choose between them both.  Waterfall could be applied to virtually any type of (IT) project. Agile requires specific conditions to be in place to be possible but is not applicable to certain projects – especially those of a large physical nature.  Most of the conditions required for Agile to be possible relate to the working environment and practices that can and cannot be employed by the whole project team, not just those responsible for the development. There also needs to be flexibility around requirements together with the capacity to deliver and accept product incrementally.

Waterfall may be the best choice if there is no (or limited) access to a customer to provide constant feedback. It will also suit projects with a dispersed team, fixed budget, and scope.

Agile looks preferable for more complex and larger projects, where there is easy access to customer feedback. Its flexibility makes Agile more suitable for projects with constantly changing requirements.