Bottlenecks
A bottleneck limits how much work a process can complete. Relieving it can increase output, while speeding up other stages may only add to the queue. After a change, check which stage now limits the process.
THE IDEA
Bottlenecks
A “bottleneck” is a stage whose available capacity limits the flow of work through a process. Like the neck of a bottle, it restricts how much can pass through. Its importance depends on demand, capacity, and how the stages connect, rather than on which individual task takes longest.
No one wants to be a bottleneck, which is easily conceptualized as that person who makes everyone else wait. We see this behavior in people who can’t delegate. If you insist on making every decision yourself, there’s likely a long line of people twiddling their thumbs as they wait for you to move their projects forward while you are overwhelmed.
Bottlenecks tend to create waste as resources pile up behind them. In manufacturing, they limit how much you can produce and sell. If you work in an industry that depends on timely information, then you risk inputs becoming irrelevant before they make it through the bottleneck.
A bottleneck is also the point that is most under strain. It can be the part that is most likely to break down or has the most impact if it does. To increase throughput, examine the bottleneck first. Speeding up an earlier stage may simply increase the queue. Other changes can still improve quality, reliability, or cost, even when they do not increase throughput.
Once you relieve a limiting stage, another stage may set the process’s maximum capacity. A process can also have enough capacity to meet current demand without a persistent queue. You can, however, anticipate bottlenecks and plan accordingly. Or you can leverage the need to overcome them as an impetus for finding new ways of making a system work. Sometimes you can overcome bottlenecks by adding more of the same, such as dedicating more resources to ease the pressure on a bottleneck. But sometimes the sole solution is to rethink that part of the system.
Liebig’s Law of the Minimum
Liebig’s law of the minimum refers to the idea that a plant’s growth will be limited by the nutrient in shortest supply relative to the plant’s requirements. Yield is thus constrained by resource limitation.
Avoiding Worse Bottlenecks
What you want to avoid is opening one bottleneck only to create additional, worse ones for yourself later. If bottlenecks are unavoidable, we at least want them to be in a less disruptive place.
Bottleneck vs. Constraint
The terms are used differently across fields. In the distinction made here, a bottleneck is a capacity limit that can be alleviated, while a constraint is a more fundamental limit. So a machine that keeps breaking down is a bottleneck, but the fact that there are twenty-four hours in the day is a constraint.
False Dependencies
A stated dependency may not be the actual limit. Consider the claim “I won’t do X before Y.” Ask whether Y is necessary, or whether some useful work on X could begin now. For example, you might say you will start writing every day once you move and have a dedicated desk for it. If the bottleneck is a lack of a suitable workspace, then moving will alleviate it. But if the bottleneck is something else, like time or ideas, you’re setting up a false dependency. The bottleneck will still be there once you move. Even if the problem is your workspace, you could still find ways to make progress, such as by going to the library or reading source material. Anything you do now will make it easier to get into the habit of daily writing.
If you think you’ve identified a bottleneck, it’s a good idea to do what you can to validate that this is indeed the limiting factor. Otherwise, you might end up solving the wrong problem.
When to use it
Optimizing a factory production line to increase throughput by identifying and upgrading the slowest machine
Streamlining team workflows by finding the step where tasks most often get stuck and reallocating resources
Designing a personal productivity system by honestly assessing what activity or habit constrains daily accomplishments
Map a project’s dependencies and shared resources, then check whether limited capacity is creating queues or delaying completion.
FROM THEORY TO EVERYDAY LIFE
In practice
The Delegation Bottleneck
A manager who insists on making every decision creates a bottleneck. As projects pile up, team members are left waiting, unable to move forward without approval, while the manager becomes overwhelmed.
Manufacturing Slowdown
An assembly-line machine cannot process parts as quickly as they arrive. A queue builds in front of it, and its capacity limits the line’s output until the constraint is relieved.
False Dependency in Writing
An aspiring writer claims they will start writing daily once they move and have a dedicated desk. If the real bottleneck is a lack of time or ideas, the dedicated desk is a false dependency; the bottleneck will still exist after moving.
Information Delay
A financial analyst relies on a slow data pipeline. By the time market data is processed, opportunities have vanished, rendering the inputs irrelevant.
Software Development Bottleneck
A software team submits changes faster than reviewers can assess them. Unreviewed code accumulates and delays releases; completing more code alone would add to the queue.
A MOMENT TO REFLECT
Put it to work.
What is the single part of your current project or workflow that is most limiting your output?
Are there any tasks you're avoiding by creating a false dependency, claiming you need something else to happen first?
How can you validate that what you've identified as a bottleneck is truly the limiting factor, and not just a visible point of strain?
Often confused with
CONTINUE THE CONVERSATION
Source texts
- The Great Mental Models Volume 3 Systems and Mathematics