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Blink 3 of 8 - The 5 AM Club
by Robin Sharma
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Assumption-Based Planning summary
James A. Dewar
A Tool for Reducing Avoidable Surprises
20 mins
Brief summary
Assumption-Based Planning guides us through a strategic approach to managing uncertainty in complex projects. James A. Dewar emphasizes identifying critical assumptions and developing adaptive plans to anticipate and address potential challenges effectively.
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Assumption-Based Planning
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Why plans actually fail
Think about the last time you made a detailed plan for something that mattered. Maybe it was a romantic dinner, a product launch, or a career move. You listed every step, checked your budget, mapped out the timing. It felt solid, like a roadmap to success. But here’s the thing: what you actually built was a structure held up by invisible beams. And when plans fall apart, it’s rarely because the vision was flawed or the execution was careless. It’s because one of those invisible beams snapped.
Those beams are called assumptions. An assumption is a judgment about some characteristic of the future that sits underneath your plans. It’s the gap between what you know for certain and what you need to be true for everything to work. When you look at your strategy, you see a list of actions. But if you could x-ray that plan, you'd find every action rests on a foundation of judgments like these. Some are rock-solid. Others are fragile. The trouble is, in the rush of planning, you often forget you’re making them at all.
So, how do you figure out which beams actually matter? Think like an architect examining a blueprint. You can knock down a partition wall and the roof stays up, but remove a main support column and part of the building comes crashing down. The same logic applies to strategy. You need to identify load-bearing assumptions: the ones whose failure would force you to completely rethink your plans.
Here’s a quick example. Say you have a project timeline that depends entirely on a key employee named Sylvia. You’ve planned for her tasks, her hours, her output. But underneath that schedule sits a silent beam: the assumption that Sylvia will actually be there. If she’s constantly being recruited by competitors, you might worry about this openly. But what if Sylvia is intensely loyal and has never missed a day? Her presence starts to feel like a fact rather than an assumption. You stop noticing that your entire operation rests on her showing up.
This brings us to the most dangerous category: the implicit assumption. These are judgments you’re not even consciously aware you’re making. They’ve slipped below the surface of your attention, often because familiarity has hardened them into something that feels like certainty. In Sylvia’s case, her loyalty makes her availability seem guaranteed. But if she’s suddenly unavailable – a family emergency, an unexpected illness – that implicit beam snaps. Because you didn’t know it was there, you have no backup. The plan collapses.
Traditional planning often encourages you to focus on the decoration – the goals, the marketing, the rollout – while ignoring the structural integrity underneath. To build a strategy that survives contact with reality, you have to stop looking at what you plan to do and start looking for what you’re expecting to happen. You have to find those invisible supports before they buckle. But how do you spot a risk you don’t even know you’re taking?
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What is Assumption-Based Planning about?
Assumption-Based Planning (2002) offers a different way to think about strategy. Instead of trying to predict what the future holds, it gives you a method for finding the weak points in any plan – the silent beliefs that, if they turn out to be wrong, bring everything down. You'll walk away with practical tools for stress-testing your goals and making them sturdy enough to survive surprise.
Who should read Assumption-Based Planning?
- Project managers who want to catch risks before they become problems
- Entrepreneurs operating in unpredictable markets
- Corporate strategists who need plans that can take a hit and keep standing
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