Project Methodologies – Which one is right for me?

The majority of people think of project management (PM) methodologies as blueprints, step-by-step instructions that guide the delivery team on how to build a successful project to deliver. They’re not. That’s not to say they’re without value, quite the contrary, they’re just not blueprints.

With so many different methodologies it’s hard to decide which way to go. How can an executive know which is the right one to manage the complexity of your program? Which one will guarantee success and deliver within agreed tolerances?

As with anything, it’s important to understand the relative strengths and weaknesses before making a decision. This is typically mired in jargon that seems designed to confuse so I’ve provided a quick, plain language definition of the most commonly used options.


Developed for projects requiring significant flexibility and where the end-end picture is evolving.

Agile is highly iterative, allowing for swift adjustments throughout a project and is be best suited for small to medium sized projects (e.g. product developments where multiple variants exist or are required). To make it work you need a self-motivated team with decision making autonomy.

While Agile methods are widely used across multiple industries and are known to have built-in quality management system, there are challenges around assessing the quality in terms of delivery output (scope), progress (time) and costs.


Downwardly sequential in nature with static phases executed in an exact order. Waterfall is seen by many as the ‘traditional’ approach and is used across many industries such as aviation, construction, defence.

Waterfall gives increased control and structure but flexibility can suffer when unanticipated scope changes occur. Waterfall being a traditional delivery method means quality assurance is report based relying on periodic inspections, and can be seen as more reactive than proactive.

Critics see the large investment in creating ‘certainty’ over scope and approach upfront as tedious and costly. That said, managed well the control and structure can ensure tight financial reigns are applied.

Critical Path Method (CPM)

Visual and mathematical, this step-by-step methodology is often used for large projects with interdependent activities, particularly those in the manufacturing and construction.

It contains a list of activities and uses a work-break-down structure (WBS), a timeline to complete and dependencies, milestones, and deliverables.

It outlines critical and non-critical activities by calculating the “longest” (on the critical path) and “shortest” (float) time to complete tasks to determine which activities are critical and which are not.

It’s got obvious upsides for management transparency but has a tendency to drive focus more on time than quality and costs.


This one is a part of the agile framework for managing complex development efforts and, like Agile, is iterative in nature.

“Scrum sessions” are used to prioritise tasks and a Scrum Master facilitates a sprint (usually 30 days) instead of a project manager. Small teams are assembled to focus on specific tasks independently and then meet with the Scrum Master to evaluate progress or results and reprioritize backlogged tasks.

Scrum relies on stakeholders working collaboratively through a journey of agreed sprints with a value of ‘learn and test as you go’. Scrum is exceptionally dependent on the quality of the people involved.

Risky when you’re new to it, but powerful once your teams are well versed

The winner is…

Applying any of these delivery methodologies and following recognised standards, like Organisational Project Management Maturity Model (OPM3), will strengthen alignment between business planning and execution performance.

Everyone has their own ideas and what they may regard as best practice, is it Agile, Waterfall, or is it fly by the seat of your pants, or just yell and get it done. The truth is there is simply no right (or wrong answer). In my experience, it’s usually a hybrid of them all that gets the best results.

All of them can work.

With more years of independent assurance experience than I care to mention, what I do know irrefutably is that the major differentiator for success is the quality and engagement level of the leader. The shiniest tools with the fanciest methodology are worthless without exceptional leadership. But that’s a subject for a whole different blog.

Noel O’Kelly is Principal Consultant, Assurance at Sequential.