20 June 2019

Project Planning in Software Development: Agile vs Waterfall


Agile vs Waterfall – a constant battle in software development world. Whatever your project, timeline, and conditions, there’s a methodology out there for you.

Every new IT project can be the journey of a lifetime. Sometimes, these journeys face a fork in the road – where two possible paths appear.

Both paths lead to success, but specific characteristics will determine the particular path you should take. And, while all roads eventually lead to Rome, depending on the demands, conditions, and scope of your project – you will need to choose between two leading schools of thought.

None is universally advantageous over the other, and in fact, depending on current circumstances, you can be sure to benefit from one of the main types of project methodology: Waterfall and Agile. This is also known as ‘organising the work of software development.’

Specific timeframes, budgets, and specifications will determine the best path. In this instance, Agile & Waterfall will work best with only certain kinds of projects.

I welcome you to the first of my series of articles, where I will explore the worlds of both methodologies, and how each applies to specific IT projects.

Here’s what you’ll learn in this article:

  1. The Old School: Waterfall
  2. The New School: Agile
  3. List Your Priorities – Then Pick Your School
  4. In a Nutshell: Agile vs Waterfall

Two Schools of Software Development Methodology

1. The Old School: Waterfall Software Development

I’d like you to imagine an Olympic relay race. It is ruthlessly demanding. It is strict. But achieved well, it is an act of glory.

As one athlete sprints around the track, they must pass the baton to their teammate before their fellow teammate can begin. Then, and only then can they run, carrying the baton onto the next person. This process repeats until each runner has completed their lap.

And like this demanding sport, Waterfall’s workflow is divided into consecutive phases, with each role passing its deliverable on to the next step.

The essential characteristic of this software development methodology is the system’s rigidity. And in the context of a project, upon completion of the plan, there can be no further changes to the applied methodology. Once you’re in a waterfall you can’t swim back up! Therefore, once a project stage is complete, then you must proceed on to the next.

Developer communications limit throughout this process. High-Low Interaction in Waterfall means high levels of interaction occur during Analysis and Tests. On the other hand, there’s a considerable lapse of communication during Development and Tests.

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2. The New School: Agile Software Development

This time, Rugby is the game most fitting to this methodology.

In this team sport of 15-per-side, the objective is to kick or carry the ball into the endzone of the opposing team. It is a high-intensity sport, with a very notable feature – you cannot pass forward, only backwards, or sideways. This means the trajectory at which the ball advances across the field, is somewhat ‘circular’, as players pass and advance through the field with the rugby ball until finally reaching their objective.

As a project methodology, Agile demands interactions in development and testing through the software development process. It is mainly devoid of schedules and tasks, whereby the timetable splits into several time-boxed iterations, also known as sprints.

Initial requirements can be updated following all sprints’ completion, enabling the processes to start again. While this happens, different projects may also start.

Notably, this method features constant business interaction, with participation possible from stakeholders in analysis, design, tests. The operation runs feature-by-feature and adapts to change with any adjustments you may need to make to the project. In all, it is a far more responsive system.

Agile process diagram.

Each of the incremental sprints lasts a total of 1-4 weeks, depending on the project. And in a clear distinction to Waterfall software development, there is a great deal of flexibility, where changes are very much permitted, even following plan completion.

List Your Priorities – Then Pick Your School

As I mentioned earlier, you’ll have objectives, with set tools and rules at your disposal. Based on these following scenarios, we can determine which methodology works for you.

Let’s begin:

“I have a well-defined maximum budget, stable requirements, and a very small risk of change during the project.”

Verdict: Waterfall

Waterfall operates as if ‘inside of a vacuum’, whereby you enter the requirements and await the result. Therefore, if all aspects remain unchanged within the development, then this highly-disciplined process is the optimal method for your project.

“I have only general requirements that need refining and changing during the project. I may increase the project budget.”

Verdict: Agile

The Agile development process is most accommodating to incremental changes throughout the entirety of the project. If you plan to make further adjustments at a later time, then this will be most suitable to your project.

“I need to be involved in all stages of development.”

Verdict: Agile

This option permits interaction during any stage of the project. Should you, or even the developer request regular feedback and verification, then you can benefit from this method, as it encourages ‘follow ups’ between clients anddevelopment teams. If you seek involvement – then Agile is best.

“I have an exact delivery deadline – we’ll iron out the ‘Kinks’ later.” 

Verdict: Waterfall

Strict timeline mindfulness is a fundamental aspect of this method. This well-disciplined system keeps developers in-line, preventing them from going off-track, as can happen in Agile. This system essentially permits clients to agree early in the cooperation, for developers to ‘get on with the task’.

Quality is my top priority. No glitches or bugs can be permitted in the final product.”

Verdict: Agile

An emphasis on involvement and constant re-evaluation means fixes happen throughout the process. Your Agile team is organised and self-motivated, with a keen eye on early problem detection. From a quality point of view, there is a low risk of bugs in the final product.

“I’m working on a small-scale project, and quality is also my top priority.” 

Verdict: Waterfall 

Smaller projects present a lower risk for potential issues, as they generally feature more understandable requirements. Because of this, you can confirm specifications confidently from the beginning, maintaining high integrity, with less instance of a ‘piecemeal’ project. 

“I want to keep my project design options open for later.”

Verdict: Agile

Flexibility defines the Agile methodology. This system is very open to changes throughout the development process. Teams are interchangeable, respond well to adjustment requests, and can build the basic software first, then allow for iterations at a later stage. Furthermore, if a project aspect no-longer seems satisfactory, due to time or shifting preferences – you may fine-tune it as you see fit.

In a Nutshell: Agile vs Waterfall

As you can see, both Agile and Waterfall software development are two exceptional schools of thought. Both cater to a unique palate of requirements, priorities, and project features. In several cases, project requirements and conditions mean the schools are mostly mutually exclusive to one another.

Project Size Decides Method

Agile – Larger

Agile excels for larger projects. As grand-scale projects break down into smaller areas, there is greater attention then given to the quality of the final product.

Waterfall – Smaller

Waterfall suits for smaller projects. The structured process is designed for simple-to-understand projects, as it takes instructions from the onset, engaging until the end.

Quality vs Delivery Trade-Off

Agile – Quality

Agile emphases on quality at all stages of development. This ensures a quality project, at the expense of time. Timelines are often derailed, with extended stretches frequently required to complete projects.

Waterfall– Time

Waterfall, on the other hand, sticks to the timeline, sometimes at the expense of quality. Due to no time for discussions and verifications, software issues can only be detected later in the project.

Involvement vs Autonomy

Agile – More Involvement

Agile permits high levels of involvement, which is positive for clients wishing to provide constant input, or developers seeking regular feedback.

Waterfall– More Autonomy

Waterfall however requires only minimal feedback, in the beginning, and end stages of development. Clients who seek less involvement, or developers requesting greater autonomy both favour this option.

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Rene Koelblen
Regional Sales Director /France

Experienced Commercial Director with a demonstrated history of working in the information technology and services industry. Strong business development professional skilled in Business Process, Requirements Analysis, Translation, ITIL, and IT Service Management.