Author: James A. Dewar
_James A. Dewar_
Reading time: 20 minutes
Synopsis
Assumption-Based Planning (2002) shows a new way to think about plans. You don’t try to guess the future. Instead, this method helps you find the weak parts in any plan. These are the hidden ideas that, if wrong, can make everything fail. You will get useful tools to check your goals. These tools will help your goals be strong enough for unexpected problems.
What’s in it for me? Learn to see the hidden beliefs in any plan – and turn them from weaknesses into strengths for your plan.
We all want to be sure about things. So, when we make plans, we often imagine a clear path from today to our goal. We put important steps along this path that feel strong and real. It feels good to imagine the project finished – a successful business, a goal reached. But deep down, you might feel a small worry. You know that computer charts cannot deal with unexpected problems. The strong feeling we have might just be a story we tell ourselves. We do this to avoid thinking about what we don’t know.
This summary will show you the truth. You will look under your goals and find the main hidden ideas. These ideas decide if your plans will work or fail. When you can see these hidden parts, you will stop just hoping things work out. You will become someone who makes plans strong enough to handle the problems that life will surely bring.
Blink 1 – Why plans actually fail
Think about a time you made a detailed plan for something important. Maybe it was a special dinner, a new product, or a career change. You wrote down every step. You checked your money. You planned the time. It felt strong, like a map to success. But here is the truth: what you built was held up by hidden supports. When plans fail, it’s usually not because the idea was bad or you worked carelessly. It’s because one of those hidden supports broke.
These supports are called assumptions. An assumption is an idea about the future that your plans depend on. It is the difference between what you know for sure and what needs to be true for your plan to work. When you look at your plan, you see a list of actions. But if you could look inside that plan, you would see that every action rests on ideas like these. Some are very strong. Others are weak. The problem is, when you are busy planning, you often forget you are making these ideas at all.
So, how do you find out which supports are most important? Think like a builder looking at a house plan. You can remove a small wall and the roof stays up. But if you remove a main supporting part, a piece of the building falls down. The same idea works for your plans. You need to find the main assumptions. These are the ones where, if they fail, you would need to change your plans completely.
Here is a quick example. Imagine you have a project plan that fully depends on a key worker named Sylvia. You have planned her tasks, her hours, her work output. But under that schedule is a silent support: the idea that Sylvia will be there. If other companies try to hire her often, you might worry about this openly. But what if Sylvia is very loyal and has never missed a day? Her being there starts to feel like a fact, not an assumption. You stop noticing that your whole project depends on her showing up.
This leads us to the most dangerous type: the hidden assumption. These are ideas you do not even know you are making. They have moved out of your mind. This often happens because they feel so familiar that they seem like facts. In Sylvia’s case, her loyalty makes her availability seem certain. But if she suddenly cannot come – because of a family problem or unexpected sickness – that hidden support breaks. Because you did not know it was there, you have no backup plan. The plan fails.
Normal planning often tells you to focus on the outside parts – the goals, the marketing, the launch – but not on how strong the plan really is. To build a plan that works in real life, you need to stop looking at what you plan to do. Instead, look for what you expect to happen. You must find those hidden supports before they break. But how do you see a risk you do not even know you are taking?
Blink 2 – Finding the hidden risks
To find these hidden dangers, think of your plan documents less like important writings and more like a crime scene. You are looking for clues – signs of ideas that shaped the plan but were never clearly said. The best tool for this is simple: grammar. The words you use to talk about the future show how sure you feel about it. This feeling of certainty is exactly where hidden assumptions are.
Start by looking for the word “will.” When people write plans, they use “will” all the time. For example, “Competition will be hard,” or “Technology will change the industry.” These sentences look like facts, but they are really guesses. By checking your documents for every “will,” you can find the times when you stopped seeing many possible futures. Instead, you chose only one path. Each “will” is a main assumption that needs to be checked.
The next word to look for is “must.” Planners use it to describe actions they think are absolutely necessary. For example, “We must cut staff,” or “The delivery system must handle more orders.” These “musts” are the main supports for how you plan to deal with the future. “Will” shows what you believe about the world. “Must” shows what you believe about your own abilities and limits. If you only look at the “wills” and “musts” in a document, you will see a simple map of what you are sure about.
But grammar can only help so much. To find assumptions hidden even deeper – the ones never written down – you need to look at the plan’s logic itself. Think of this as working backward from the “therefore” in your plan. Every action is there to solve a problem or take a chance. You should be able to link each action to a specific idea about the future. If your plan includes a big budget for a new factory, there is a hidden “therefore.” It links the factory to the belief that demand will increase.
Problems appear when you find actions that seem to have no link. These are expensive projects that do not connect to any stated idea. People making plans rarely do useless things. So, an action with no clear link usually means there is a strong, unstated assumption. Maybe you are building that factory because you think having extra space will make competitors afraid. Even if no one ever wrote that down. By forcing yourself to connect every “what we are doing” to a “why we are doing it,” you bring these silent reasons into the open.
After doing these careful checks – finding the “wills,” the “musts,” and the missing “therefores” – your view changes. What looked like a clear path now seems like a dangerous field. You started with a few clear risks. Now you might see dozens, even hundreds, of assumptions. This creates a new problem: you might feel stuck. You cannot watch or protect against hundreds of changing things. So, the next step is to find out which of these assumptions can really destroy your plan. And which ones you can safely ignore.
Blink 3 – How to check if something is possible with the Rip Van Winkle Test
Having a very long list of hundreds of assumptions can make you feel stuck. It feels less like a useful tool for your plan and more like a sign that your whole project is bad. If you try to protect against every small problem in the foundation, you will run out of time and money before you even start. You need to choose what is most important. You need a very strict way to separate small worries from big problems. The goal now is to find which of these many assumptions are very important for your success and could really break.
Most planners first want to ask, “What are the chances?” They look at a risk – for example, a competitor lowering prices – and try to give it a percentage, like 10% or 50%. This is a trick. Trying to guess the exact chance of a unique future event is often just guessing, but with numbers.
A better question is: Is this possible? Could it happen during the time of your plan? If yes, see it as a weak point. At this stage, it is better to think negatively than positively. You want to find every support that could break. By changing your standard from “likely” to “possible,” you stop arguing about numbers. Instead, you start focusing on how things work.
So, how do you find the really important weak points among all the unimportant things? There is a strong idea game called the Rip Van Winkle technique. It works like this: you fall into a deep sleep today and wake up twenty years later. You do not know what happened to your industry, your market, or your company. You can ask exactly ten yes-or-no questions to find out if your company survived and did well. You cannot ask, “How is the economy?” You must ask something like, “Did interest rates stay below five percent?”
This exercise quickly clears away unimportant things. When you only have ten questions to decide your future, you stop caring about small details. You do not ask about office paper costs or software updates. You ask about the main things that make your business work. The specific rules that could have made your product illegal. The specific competitor who could have made you useless. The specific customer behavior you were depending on.
The questions you choose show you the main, weak assumptions you are making today. These are the risks that matter. These are the few important supports that, if broken, will make the whole plan fall down.
By using this way of thinking, your too-long list of hundreds becomes a small, clear list of important threats. You have removed useless information and found important clues. You know exactly which assumptions are holding up the roof. And you know it is possible for them to fail.
But finding danger is only half the job. Knowing a support might crack is helpful. Knowing when it is starting to crack – that is what lets you act in time.
Blink 4 – How to set up your warning system
Building a warning system for your plan starts with a simple idea. By the time a big problem actually happens, it is too late to plan. You cannot buy fire insurance when the kitchen is already burning.
To stay safe, you need to find clear events that act as early warnings. These are signs that a main support is starting to break before the plan fails. In Assumption-Based Planning, these signs are called signposts. A signpost is a clear event or limit. It shows if an assumption is still true. It is different from a general worry like “the market might change.” Instead, it is a clear alert like “sales have gone down for three weeks in a row.”
It is easy to mix up these warning signs with your goals. But they are for completely different things. In planning, you usually focus on targets. These are things you want to achieve, like making $50 million in sales or launching by Christmas. Targets measure success. Signposts find failure.
If your plan expects you to reach that $50 million target, a signpost is not failing to reach it in December. That is just looking back after the problem. A true signpost would be missing an early sign in April. For example, maybe you only raised $30 million when your plan needed $40 million. Seeing that problem early gives you months to change. Waiting until the final deadline gives you only sadness.
Here is the important point: a signpost is only useful if it gives you time. Imagine yourself driving at night on a road you do not know. You depend on street signs to tell you when to turn. If a sign is hidden by tree leaves and you only see it as you drive past, it did not help you. It just showed your mistake.
This idea of warning time is the most important thing for setting up your defense system. Does this warning give you enough time to react? If the warning happens at the same time as the problem, it is not a signpost. It is just the sound of the crash.
Think about a child’s lemonade stand. The young seller believes the weather will be sunny on Saturday. If it rains, the business fails. Looking out the window on Saturday morning to see rain? That is useless. The lemons and cups are already bought. The money is lost. The real signpost here is the weather forecast on Friday. That forecast is a clear event that happens before it is too late. If Friday’s forecast predicts storms, the seller can decide not to buy the sugar. They can save their money for a better weekend.
So, what do you do when you look at a weak assumption and know there are no early warnings? What if the problem is too sudden for your radar to help? Then just watching is not enough. You cannot just watch the warning system. You must make your plan stronger. When you have no warning time, you must stop looking for problems. Instead, start building protections that are lasting, working, and ready for anything.
Blink 5 – Control the world, or protect yourself?
Once you accept that some problems come without warning – that the danger is too hidden or too sudden for your warning system to help you – what you need to do changes. You cannot just watch for problems anymore. You must move from just watching to actively building. You have found the hidden supports for your plan. You have checked how weak they are. You have set up your early warning systems. Now comes the last step: making them strong.
There are two ways to make a plan strong. They are very different ways of thinking about the future.
The first is shaping – trying to control things. When you find a weak assumption, for example, that customers will like your new technology, a shaping action is an active step. You take it to make that assumption come true. You do not just hope for demand. You start a strong education campaign to create it. You are acting now to make the support strong and remove the risk completely. Shaping feels like good leadership. It believes that with enough effort, you can make the world fit your plan.
But you cannot control everything. The weather, the economy, what competitors do – these are often things you cannot change. This brings us to the second way: hedging.
If shaping is about control, hedging is about insurance. It means you are humble enough to admit that a main support might still break, even if you try your best. If your plan assumes your car will take you to a meeting, a shaping action is getting the car fixed. A hedging action is putting a spare tire in the car. You do not buy that spare because you want a flat tire. You buy it because you know it is possible to get one.
The problem with hedging is rarely about ideas. It is usually about culture and money. In business meetings, shaping actions are easy to agree on. Spending money to be the best in the market sounds like progress. Hedging looks like a waste. Why build a second way to get supplies if the first one works? Why keep extra money when you could invest it in growing? For a manager who likes things to be efficient, hedging looks like a useless cost.
To deal with this problem, change how you talk about it. A plan without protection is not efficient. It is weak. It is a risk that works only if everything goes perfectly. By refusing to protect yourself, you are giving up your safety, not making money. Talk about hedging as buying choices. It is the price you pay so that one broken assumption does not destroy everything.
This whole process changes you from just hoping for the best to being ready for anything. You find your hidden ideas. You decide which weak points are most important. You set up warnings. Then you control or protect against the risks. Your plan changes. It stops being a strict plan that breaks easily when problems start. It becomes a strong, flexible system. One built to deal with the future that actually comes.
Final summary
In this summary of Assumption-Based Planning by James A. Dewar, you have learned that the real danger to any plan is not bad work. Instead, it is the hidden assumptions that quietly support the whole plan.
Do not try to guess the future. Your job is to be like a builder who makes sure buildings are strong. Find the ideas your plan needs. Then, find out which ones could break under pressure. You learned that words like “will” and “must” are warning signs that show hidden risks. Also, imagining yourself in the future helps you separate the weak assumptions from the strong ones.
Signposts give you an early warning system. They help you notice problems starting before the whole plan fails. For protection, you have two choices: shaping actions that try to make the world fit your plan, and hedging actions that get you ready for when the world does not fit. This is the change from just hoping to being truly prepared. You stop planning for the world you want. You start building for the world that really comes.
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Source: https://www.blinkist.com/https://www.blinkist.com/en/books/assumption-based-planning-en