AGILE(Incremental) vs. WATERFALL(Predictive) Project Management

Being a project management professional working in WATERFALL based project development, AGILE methodologies excites me every time I learn more about it. AGILE methodologies help to overcome some of the fundamental fears (like managing late changes, adapting to changing market demands etc.) of all organisations and project managers. Although it is actually the project environment that finally decides if AGILE, WATERFALL or a Hybrid approach will fit the best, AGILE methodologies focus more on adaptability and product features rather than sticking to project agreements.

In this article, I am trying to compare some interesting facts I learned about AGILE project management with respect to the WATERFALL model that I am familiar with.

How to decide between AGILE and WATERFALL Models?

I think this question answers itself if you can answer one of the following questions during project selection or initiation phase:

Does your customer know what exactly he wants?

OR    

Do you know what exactly you want to create/build?

If there are uncertainties about what is expected and how the final output is going to look like, then probably AGILE methodologies might fit your needs better. Of course there are other factors like project environment and constraints which finally contributes to this decision but answering above question might already give you a very strong first hint.

Below is comparison of some key aspects both methodologies:

Distressing vs. Embracing Change

In WATERFALL based project management, the biggest challenge is managing changes efficiently throughout the project with minimal impact to Scope, Time and Cost.

Whereas AGILE frameworks like SCRUM and XP focus on incremental changes and continued integration. In the AGILE world, you should welcome and embrace these changes, even if they occur late in the project. For projects where specifications and scope will evolve over time this is a great approach, however I assume this comes with a cost of re-work and a “flexible” iron triangle (Scope, Time and Cost).

Focus on Reporting vs. Incremental Product Delivery

Projects following WATERFALL frameworks believe in regular reporting to make sure that the project is progressing on track including methods like Earned Value Analysis (EVA) or joint reviews. Status of the project is judged mainly by how well the project is being executed according to the agreed plan.

Projects following AGILE methodologies aim at delivering actual product focusing on the most important features first. Customers are able to experience and provide feedback on development using the product or even consider pivoting before it's too late and before a lot of resources and costs are spent on the project.

Focus on Project Commitments vs. Product Features

Although WATERFALL model works with rolling wave planning, success of the project (and Project Manager) is greatly judged by how well the project was executed within agreed commitments (time, cost, resources etc.)

AGILE methodologies focus on product with maximum value in minimum time rather than current project or agreements. During short term sprints, AGILE teams incrementally delivers product with more and more features continuously integrating changes and new ideas

The way I see it is shown below:

Gantt Chart vs. Burndown Chart

WATERFALL model shows a Gantt chart to show the planned tasks and its dependencies over time, in AGILE world a Burndown chart shows how well the team is able to finish the planned features during incremental deliveries or spirits. 

Although we see benefits for AGILE methodologies in above comparison, WATERFALL frameworks are still preferred framework in many industries due project constraints, need for agreement and Statement of Work (SOW) sign-off based on clear project scope.

The most important criteria for success of a WATERFALL framework is having a customer who clearly knows what he wants. If this criterion is satisfied, WATERFALL model can be more practical than AGILE model. For organisations with multi-level project hierarchy and products involving complicated value chains might find difficulties to adapt AGILE methodologies.

Summary:

AGILE methodologies overcome some of the major challenges faced in the WATERFALL model. However, for organisations or teams to decide which method to follow depends on many internal and external factors. I believe a realistic hybrid approach will evolve over time taking advantages from both methodologies.