A Comparison of Project Management Methodologies: Agile vs. Waterfall

As you may know, a software project requires a company to make a lot of decisions. One of the first decisions would be about the software development approach. Traditionally, Waterfall methodology was adopted for project management. But since the introduction of Agile, things have taken a turn. But what is it that makes Agile better than Waterfall with respect to software project management?

Development methodology essentially involves organizing the software development phases. Both Agile and Waterfall serve that purpose but in fundamentally different ways.

To get a better idea before we begin, here’s a list of the development stages involved and a short description of the two concepts.

  • Waterfall – A traditional approach to software development, the development stages are carried out in a linear sequence.
  • Agile – A rapid application development methodology implemented using Scrum. It has been around for a while and not exactly something new.

The development stages include Conception, Analysis, Design, Development, Testing, Implementation, and Maintenance.

Waterfall Methodology

It’s akin to the construction of a building, starting with conception, analysis, and construction. The methodology requires developers to finish one stage to move on to the next. It’s sequential and linear which means the developers can only go forward to the next step. They cannot move back to the previous stage unless they scrap the whole project and start anew.

This means that the development team can’t afford to make a single mistake that would require changing what they have done in the previous stages. This also calls for a well thought-out plan that should be followed over the course of the development.

But there are merits to the Waterfall model as well.

  • Clients will know what to expect from the delivered product during the early stages of development.
  • Developers can plan and design accordingly after agreeing on the product features early in the development stage.
  • Easier to measure progress, as the methodology demands scrupulous record keeping.
  • Clients need not be present for the later stages of development once the requirements are gathered.

That’s the positive side. The disadvantages include:

  • Developers won’t be able to go back to completed development stages to make changes.
  • If the initial requirements aren’t accurate, the project will most likely not succeed.
  • To make changes in the project, developers will have to start all over again from scratch.
  • Testing phase comes later in the lifecycle, which means some bugs written in earlier stages are likely to be discovered late. This can affect the code and the product as a whole.
  • If the client wants to add new things to the product on the go, it can delay the project while also impacting budget.

Agile Methodology

Unlike Waterfall, Agile is an iterative approach to development, and dependent on the team. The methodology is designed for rapid delivery of a fully functional product. There will be multiple iterations in the development lifecycle, generally referred to as ‘Sprints’. Each sprint will have a predetermined duration and objectives with a list of deliverables as per the plan. These deliverables are given priorities based on client requirements.

If the developers were unable to complete a sprint according to plan, the information is logged for future planning, and they change the work priorities. The project team and the client will be able to evaluate and review the progress of the project after each sprint.

So, the advantages are:

  • Client will have the opportunity to work closely with the developers throughout the development lifecycle, and make changes whenever necessary.
  • As it’s easier to make changes and code rewrites are expected, it will be easier to add features that keep the product up-to-date with the latest developments in the industry.
  • Developers can provide a basic ‘beta’ version of the product built in a few successive iterations if time to market is a concern.
  • Testing will be done in each sprint which considerably increases the likelihood of a bug-free end-product delivery.

Though there aren’t many disadvantages in using Agile, for the sake of the analysis, let’s assess its vulnerabilities.

  • Client involvement is a critical factor when it comes to Agile development. But not all clients can afford the time to participate in the development.
  • The methodology requires the team to be dedicated, and led by a capable project manager. Inexperienced project managers might not be able to plan properly, thereby increasing the number of sprints and consequently, the delivery time and budget.
  • Agile is subjected to changes and frequent reprioritization. So the items set for delivery may not be delivered within the allotted time. Such changes and reprioritization may require more sprints, adding to the project expenditure and delaying its delivery.
  • The final product may be different from what was initially agreed up on, depending on the addition of features and the number of changes required by the client.

Choosing Between the Two

You may noticed the most obvious traits of the two.

Waterfall is rigid and Agile is flexible.

Rigid, but in a structured, sequential manner. There’s no going back. On the other hand, Agile gives the developers the freedom to move through and over the project as they see fit. The latter can also accommodate changes. So everything mentioned above can give you a general idea when to use each.

If the development company works with fixed-price contracts and doesn’t expect a lot of changes demanded during development, Waterfall is ideal. The requirements will be agreed upon and the clients know what to expect.

If your clients would want to make changes or add features during development or if they want the product delivered as soon as possible, Agile is the way to go.

So surmising all this zeroes in on the question whether the developers will be expecting changes during the development. If the answer is a Yes, they can follow the Agile methodology. If the answer is a No, they can go with Waterfall. At the end of the day, both methods deliver quality products. Waterfall is all about predictability. Agile is about flexibility. Choosing between the two depends on the scope of the project, requirements, client involvement, delivery period, and susceptibility to change.