A behavioural science model, an iconic van, and a practical way to diagnose the gap between policy and practice.
Most leaders don’t need another strategy document. They need an honest answer to a more practical question: why isn’t the thing we already agreed on actually happening? Why aren’t nurses preparing surgical sites the way policy says they should? Why isn’t reception collecting three forms of identification before clients arrive? Why are mobile contacts for family not being recorded when new users are added to the system?
These are not exotic problems. They are the bug-bears of every organisation — small gaps between what should be happening and what actually is. And for nearly every one of them, the reason can be traced to one of three things.
Meet COM-B: the behaviour model that explains the gap
The COM-B model, developed by Professor Susan Michie (University College London), Maartje van Stralen, and Professor Robert West in their foundational 2011 paper in Implementation Science, is one of the most widely cited frameworks in behavioural science. It sits at the centre of the broader Behaviour Change Wheel, which Michie and colleagues developed after reviewing 19 existing behaviour change frameworks and finding that none covered the full range of what drives human action (Michie, van Stralen & West, 2011).
The insight is deceptively simple. For any behaviour to occur, three conditions must be present:
— Capability — does the person have the knowledge and skills (psychological capability) and the physical capacity (physical capability) to do what’s required?
— Opportunity — do the environment, systems, equipment, and time (physical opportunity), and the surrounding culture (social opportunity), make the behaviour possible?
— Motivation — are the conscious reasoning (reflective motivation) and the habits and emotional responses (automatic motivation) pointing the person toward the behaviour rather than away from it?
A weakness in any one of these will produce inconsistent behaviour at an individual or team level. Michie’s core contribution was showing that effective behaviour change interventions are targeted at the specific COM-B element that’s actually missing — not scattered across all three in the hope that something lands.
A famous applied example: Michie and colleagues worked on the UK’s “Clean Your Hands” campaign in NHS hospitals. Training programs already addressed capability (nurses knew how to wash hands). What was missing was opportunity and motivation. So alcohol hand rubs were placed next to every bed (physical opportunity), motivational posters became nudge reminders (reflective motivation), and patients were explicitly encouraged to ask nurses whether they had washed their hands (social opportunity / automatic motivation) (West & Michie, 2020). The result was a measurable shift in handwashing behaviour — achieved not by telling nurses to try harder, but by redesigning the system around them.
How to actually use COM-B: talk, walk, try
Diagnosing the specific COM-B gap in a real workplace is surprisingly straightforward with a three-part method: talk, walk, try. Each element surfaces information that the others won’t.
Talk: Go to the team
Walk around and talk to people individually and in small groups about the realities of their workflow. What does their day actually look like? Where do things get stuck? The barriers people face across capability, opportunity, and motivation usually surface quickly in a one-to-one conversation, where they will say things they would never say in a management meeting.
Walk: Observe what actually happens
In meetings, people tend to gloss over realities and be polite. Walking around and observing what actually happens will often reveal things words can’t. How does the workspace itself interfere? How do constant interruptions break up the flow? How do long queues mean everyone feels overwhelmed and starts skipping steps? A picture is worth a thousand words — go and take a look.
Try: Examine the actual payoffs
The final review looks at what is actually being rewarded. Is there more payoff for finishing on time or processing more people than for accuracy and completeness? What financial incentives focus the team’s attention? How are staff quietly working around difficult clients or tough colleagues by avoiding certain tasks? How are they simply trying to stay sane in an under-resourced environment?
Staying sane and surviving can be a huge motivator. Attempting to perform the task yourself — or running a scenario to replicate what is supposed to happen — is often the single best way to discover how impractical the prescribed procedure actually is. Practice reveals where the design itself is broken.
Why this matters: stop blaming, start designing
One reason COM-B has had such influence in health, public policy, and workplace design is that it reframes what looks like individual failure as system design. Atul Gawande made a related argument in The Checklist Manifesto (2009): in complex work, consistent performance almost never comes from exhorting professionals to try harder. It comes from designing the right supports into the environment (Gawande, 2009).
That reframing matters, because the default managerial response to non-compliance is almost always to assume motivation is the problem — and to respond with more training, more reminders, or more performance management. COM-B asks a more useful question first: which of the three is actually missing? Often the answer is opportunity (the system is broken) or capability (the procedure is not well understood in practice), and the “motivation problem” was never really the problem at all.
Models are like toothbrushes
There is an old line in management circles: models are like toothbrushes — everyone has one, but nobody wants to use anyone else’s. The COM-B model is useful enough to deserve a better fate. Making it memorable is part of making it stick. So here is a way to remember it, courtesy of a vehicle most Australians will recognise on sight. COM-B sounds like Kombi. And the Kombi van turns out to be a near-perfect illustration of the model in action.
What a Kombi van can teach us about behaviour change
Before the Kombi, getting away for the weekend involved either the trials and tribulations of assembling a tent or the expense of booking a motel. Both required packing and being organised. The Kombi changed the economics. It gave more people the ability to explore at short notice, because the van was always ready to move. The biggest uptake was among younger people keen to see the world — or at least catch as much good surf as they could find.
The Kombi created opportunity
Suddenly, it was easy to get out and about on a limited budget with limited planning. That ease — the removal of friction, the standing readiness — drove a short-stay tourism culture unlike anything before it. Australia’s coastal communities have not been the same since.
The capability required was modest
A driver’s licence, a willingness to assemble the bed each night, and arguably a decent opening line for whoever you met along the winding road were all you needed. The advantage of having a bed in the back meant that whoever you met was relatively easy to accommodate for the next leg of the journey. Low skill threshold, high enabled behaviour.
And the motivation was… considerable
In the 1960s and 1970s it was difficult to bring your partner home for a great night in. The Kombi removed at least one obstacle. In Australia, Kombis were joined in iconic status by the “shaggin’ wagons” — Holden and Ford panel vans originally designed for tradies but enthusiastically adopted by surfers and young travellers. Petrol was cheap, horizons were distant, and the motivational architecture was self-evidently powerful.
Capability: minimal. Opportunity: engineered into the vehicle. Motivation: substantial. The behaviour followed. Much more outdoor exploration. Much more making-out and general carousing. An entire era of weekends away enjoying freedom and youth. COM-B, basically, on wheels.
From individual diagnosis to collective redesign
COM-B is a powerful diagnostic tool. But diagnosis alone doesn’t change systems. Once the gap is identified — whether it sits in capability, opportunity, or motivation — the harder work begins: redesigning the workflow, policy, environment, or incentive structure with the people who actually do the work.
This is where co-design methodologies come in. Australian practitioner KA McKercher, in Beyond Sticky Notes: Co-design for Real, sets out four foundational principles for this work: share power, prioritise relationships, use participatory means, and build capability (McKercher, 2020). COM-B tells a leader what to change. Co-design tells them how to change it without breaking the trust of the people affected.
For those wanting a structured approach, the Co.Design4All framework offers a practical 4D methodology — Discover, Design, Decide, Debrief — supported by over 100 tools across fourteen stages. The framework is designed to be accessible to anyone leading or navigating a significant change project, not just trained facilitators.
The mapping to COM-B is direct and useful:
— Discover is where the talk, walk, try diagnostic lives. It surfaces which COM-B element is actually missing and who needs to be in the room to fix it.
— Design is where capability-building, opportunity redesign, and motivation rebalancing are developed with the team, not imposed on them.
— Decide is where the group commits to the changes and agrees on how they will be implemented and evaluated. Some of those changes may involve capability uplift amongst service providers who will be required to
do new things. They will be motivated to change because the new model addresses real need and opens options for real impact.
— Debrief closes the loop with structured reflection on what worked, what didn’t, and what the facilitator and team have learned — the piece that most change projects skip entirely.
Used together, COM-B diagnoses the behavioural gap and Co.Design4All provides the participatory scaffolding to close it. Diagnosis without redesign produces frustration. Redesign without diagnosis produces activity without impact. Both aspects brought together give teams a genuine chance of moving from “why isn’t this happening?” to “here’s why, and here’s what we’re going to do about it.”
The road trip ahead
The next time a procedure isn’t being followed, the first instinct shouldn’t be to reissue the policy or repeat the training. It should be to ask three questions: Do they have the capability? Do they have the opportunity? Do they have the motivation? The answers almost always reveal that the problem is more structural than personal.
Competence, opportunity, motivation. These are the seeds of behaviour. Like the Kombi that carried a generation into freedom, get the three working together and people will travel further than anyone expected. Get them wrong, and the van won’t even leave the driveway — no matter how many times you tell the team to start the engine.
So hit the road. And bring the right model for the journey. You too might love it!
References
- Co.Design4All (2025). The 4D Framework: Discover, Design, Decide, Debrief. Available at: https://codesign4all.com
- Gawande, A. (2009). The Checklist Manifesto: How to Get Things Right. New York: Metropolitan Books.
- McKercher, K. A. (2020). Beyond Sticky Notes: Co-design for Real — Mindsets, methods and movements. Sydney: Beyond Sticky Notes.
- Michie, S., van Stralen, M. M., & West, R. (2011). The behaviour change wheel: A new method for characterising and designing behaviour change interventions. Implementation Science, 6, 42.
- Michie, S., Atkins, L., & West, R. (2014). The Behaviour Change Wheel: A Guide to Designing Interventions. London: Silverback Publishing.
- West, R., & Michie, S. (2020). A brief introduction to the COM-B Model of behaviour and the PRIME Theory of motivation. Qeios.
