By Ruth Hill and the Mind Tools Team

Unblocking Bottlenecks

Fixing Unbalanced Processes

© iStockphoto

Where are your bottlenecks?

Imagine that you own a trucking company that is experiencing some difficulties with one of its clients.

Goods get picked up at the factory without any trouble, but there are always lengthy delays at the other end, when your drivers try to deliver them to the distribution centre. Every minute the trucks are parked and waiting eats into your profits. 

What are you going to do? 

After some investigation, you find out that the reason the trucks are left waiting is because no one notifies the warehouse in advance of their arrival. Because of this, the forklift needed for unloading the trucks is often being used for another task, so your truck has to wait until the forklift is free.

Why isn't the warehouse being notified? It turns out that the person who used to call the warehouse left the company a few months ago, and the task wasn't reassigned. So, you delegate the phone call to another team member, and you persuade the warehouse to purchase a second forklift – and your problem is solved.

This bottleneck was pretty easy to fix. But have you ever discovered a bottleneck in your business processes? These can be harder to resolve, mostly because they're harder to identify.

What is a Bottleneck?

A bottleneck in a process occurs when input comes in faster than the next step can use it to create output. The term compares assets (information, materials, products, man-hours) with water. When water is poured out of a bottle, it has to pass through the bottle's neck, or opening. The wider the bottle's neck, the more water (input/assets) you can pour out. The smaller, or narrower, the bottle's neck, the less you can pour out – and you end up with a back-up, or "bottleneck."

There are two main types of bottlenecks:

  1. Short-term bottlenecks – These are caused by temporary problems. A good example is when key team members become ill or go on vacation. No one else is qualified to take over their projects, which causes a backlog in their work until they return.
  2. Long-term bottlenecks – These occur all the time. An example would be when a company's month-end reporting process is delayed every month, because one person has to complete a series of time-consuming tasks – and he can't even start until he has the final month-end figures.

Identifying and fixing bottlenecks is highly important. They can cause a lot of problems in terms of lost revenue, dissatisfied customers, wasted time, poor-quality products or services, and high stress in team members.

How to Identify Bottlenecks

Identifying bottlenecks in manufacturing is usually pretty easy. On an assembly line, you see when products pile up at a certain point. In business processes, however, they can be harder to find.

Start with yourself. Is there a routine or situation that regularly causes stress in your day? These frustrations can actually be a significant indicator that a bottleneck exists somewhere.

For example, imagine that you're responsible for reviewing a report that another team member creates each week. Once you're done, you give it to another team member, who has to post the report on your company's intranet. Due to your workload, however, the report often sits on your desk for hours – so the next person down the line sometimes has to stay later at the end of the day to post it on time. This causes a lot of stress for you as well as your colleague. In this scenario, you're the bottleneck.

Here are some other signs of bottlenecks:

  • Long wait times – For example, your work is delayed because you're waiting for a product, a report, or more information. Or materials spend time waiting between steps of a business or manufacturing process.
  • Backlogged work – There's too much work piled up at one end, and not enough at the other end.
  • High stress levels.

Two tools are useful in helping you identify bottlenecks:

1. Flow Charts

Use a flow chart to help you identify where bottlenecks are occurring. Flow charts break down a system by detailing every step in the process in an easy-to-follow diagrammatic flow. Once you map out a process, it's much easier to see where there might be a problem. Sit down and identify each step that your process needs to function well.

For example, in the trucking scenario we mentioned earlier, a flow chart might look like this:

  • Step 1 – Goods are manufactured at the factory.
  • Step 2 – Goods are loaded onto the truck.
  • Step 3 – The warehouse is notified about the truck's arrival time.
  • Step 4 – The warehouse schedules a forklift for the expected arrival time.
  • Step 5 – The truck arrives at the warehouse, and unloading starts.

In this case, the delay occurred because Steps 3 and 4 were missing, and this led to a long wait between Steps 2 and 5. Creating the flow chart before investigating the problem would have helped you quickly see where your process broke down.

2. The Five Whys Technique

The Five Whys technique can also help you identify how to unblock your bottleneck.

To start, identify the problem you want to address. Then, working backward, ask yourself why this problem is occurring. Keep asking yourself "Why?" at each step, until you reach the root cause.

Consider our trucking example again. Go back to the beginning, and imagine that you have no idea why the trucks are delayed.

Trucks are forced to wait for hours at the warehouse.


Because the forklift isn't ready to unload the trucks when they arrive.

Why isn't the forklift ready?

Because there's only one forklift, and it's used for other things. The warehouse doesn't know the trucks are arriving, so the forklift isn't scheduled to unload cargo.

Why doesn't the warehouse know the trucks are coming?

Because no one has called to tell them.

Why has no one called the warehouse?

Because the team member whose job was to call the warehouse left months ago, and no one else was assigned to make the calls.

And there's the solution. You've identified the root cause: a missing team member. The easy fix is to delegate the task to someone else.

By working backward and identifying the root cause, you can clearly see what you need to change to fix the problem.

How to Unblock Bottlenecks

You have two basic options for unblocking your bottleneck:

  1. Increase the efficiency of the bottleneck step.
  2. Decrease input to the bottleneck step.

In our trucking example, the clear solution was to increase efficiency by notifying the warehouse. How you might increase efficiency in other situations will depend greatly on the nature of the process concerned, but here are some general ideas:

  • Ensure that whatever is being fed into the bottleneck is free of defects. By doing this, you ensure that you're not wasting the valuable bottleneck resource by using it to process material that will later be discarded.
  • Remove activities from the bottleneck process that could be done by other people or machinery.
  • Assign the most productive team members and technology to the bottleneck process.
  • Add capacity in the bottleneck process.

For more on how to increase the efficiency of processes, see our article on Kaizen: Gaining the Full Benefits of Continuous Improvement .

The other option, decreasing input, may at first sound silly. But if one part of a process has the potential to produce more output than you ultimately need or can manage, it's an appropriate response. You may have a situation where you keep increasing the amount of work-in-progress inventory immediately after a step that's working too efficiently.

For example, speed cameras can "catch" a large number of drivers who exceed the speed limit. However, each speed violation has to be processed, and this incurs a cost. The cameras can catch far more drivers than the processing departments can handle. So, many cameras are programmed to identify only those drivers who go a certain amount over the speed limit, or to operate only at certain times of day or certain days of the week. As a result, the number of inputs to the system is reduced to the level that it can process.

Key Points

Bottlenecks can cause major problems for any company, and identifying their root causes is critical. Look for the typical signs of bottlenecks – such as backlogged work, waiting (by people, materials, or paperwork), and high stress relating to a task or process. To make sure you identify the root cause (and not just one of the effects), use a Flow Chart or the Five Whys technique.

To explore process balancing and resolving bottlenecks in more detail, read "The Goal" by Eliyahu M Goldratt and Jeff Cox.

Apply This to Your Life

Are there bottlenecks in any of your processes at work? Do you produce things that sit in a colleague's inbox for hours or days before they're processed? Do things sit in your inbox for days because you're too busy? Do you often wait to receive materials, reports, or pieces of information from colleagues, and do these delay tasks that you need to complete? Or are you always late sending things to your colleagues?

For each bottleneck situation, identify who – or what – the bottleneck is. Is it you, or someone else, or even an automatic process?

Then determine if the process would flow better if inputs to the bottleneck step were reduced, or if efficiency were increased. If the problem is efficiency, how can you improve? Read our article on leverage for ideas on doing this.


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Comments (2)
  • Over a month ago fxgg090 wrote
    And that is if the bottle is open, many organizations are never open to suggestions, there is zero, none input, or if there is the bottle remains closed at the top of the organization.

    Or some organizations where the leader knows when to close the bottle and when to open it, to his or her own convenience, stopping many processes or important feedback.

    If the bottle is open yes, the flow of information or inputs can really be very fast, or the amount is so big it can´t enter the neck of the bottle, or the bottle is so big, people think the amount of input is so small, but that depends on the perception and size of both the input and the bottle.

    I really liked this topic...

    Francisco González
  • Over a month ago Yolande wrote
    Hmmmm.... you see....that is exactly why we need Mind Tools. I have some serious 'bottle-necking' going on right under my nose on my own desk.... Asking "why why and why" (as per the article) will really help me sort it out. It may also mean eating ANOTHER dung beetle or two...
    But thanks...good reminder of what needs to happen. (Also reminded me of the book "The Goal").