Agile vs Waterfall, what's the difference?

Before we differentiate between Agile and Waterfall, it is important to note that Agile can be defined as a mindset to approaching projects which provides flexibility, while Waterfall offers a predefined framework to follow that is sequential in nature.

“Agile is an attitude, not a technique with boundaries. An attitude has no boundaries, so we wouldn't ask 'can I use agile here', but rather 'how would I act in the agile way here?' or 'how agile can we be, here?” - Alistair Cockburn, co-founder of the International Consortium for Agile

The difference between Agile and Waterfall

The Agile approach is having an iterative approach to delivering a project, which focuses on continuous releases that incorporate customer feedback. This provides the development team with faster product verification so they may continue to deliver iterations which align with user expectations. With today’s customers and businesses requiring rapid responses and changes, Agile provides the flexibility to adjust and iterate during the development process.

The Waterfall project management approach entails a clearly defined sequence of execution with project phases that do not advance until a phase receives final approval. Once a phase is completed, it can be difficult and costly to revisit a previous stage. Waterfall also follows a linear, sequential formula. It works well for work that has predictable and recurring processes, yet it can leave development teams flat-footed and unable to adjust faster than they should. A single missed deadline or scope change during a Waterfall project can cause outsized impacts on upcoming releases.

According to Atlassian, these are the key differences between Agile and Waterfall.

The advantages of Agile

• Faster feedback cycles
• Able to identify problems early
• Customer satisfaction has more potential
• The time to market is dramatically improved.
• Better visibility / accountability
• Dedicated teams drive better productivity over time
• There is flexible prioritisation which is focussed on value delivery.

The disadvantages of Agile

• Unlike Waterfall, critical path and inter-project dependencies may not be clearly defined.
• There is an organisational learning curve cost
• True Agile execution, with a continuous deployment pipeline, has many technical dependencies and engineering costs to establish.

The advantages of Waterfall

• Requires less coordination due to clearly defined phases and sequential processes.
• A clear project phase helps to clearly define dependencies of work.
• The cost of the project can be estimated after the requirements are defined.
• Better focus on documentation of designs and requirements.
• The design phase is more methodical and structured before any software is written.

The disadvantages of Waterfall

• Due to stricter phase sequences, it is harder to break up and share work.
• Risk of time waste due to delays and setbacks during phase transitions.
• Additional hiring requirements to fulfill specialised phase teams, whereas Agile encourages more cross-functional team composition.
• Extra communication overhead during handoff between phase transitions.
• Product ownership and engagement may not be as strong when compared to agile, since the focus is brought to the current phase.

Easy to spot differences between Agile and Waterfall

In conclusion, we have gravitated towards having an Agile approach to project management and applying the Scrum framework throughout the process. This has really helped us deliver value to our clients faster and encouraged us to collaborate more.

Sources: Atlassian Agile Coach, Customers Think and Australian Institute of Project Management.