The bowler chart, or bowling chart, is a table that is used to track the progress of an improvement project, deliverable, or task. Its name comes from the high similarity to the bowling score sheets that are used to track the progress during a bowling game. In my last post I also explained possible pitfalls with the owner, the projects, and the numeric target. This post continues with more caveats on target progression and the use of color, before suggesting a possible improvement to make the progress even more visual. (Spoiler: Use a diagram!). But, read on…
A Quick Recap and Continuation of Caveats
As described in my last post, the bowler chart tracks the progression of a project or improvement target over time (typically one year). An example is shown below.
Target Progression
Another common mistake is with the target progression. Before the beginning of the project, the target is at an initial value. At the end of the project, the measurement should be at an improved value. This improved value is the target of the project.
The simplest way would be a linear connection between the current state at the beginning of the project to the target state at the end of the project. This gradual incline represents the improvement. Unfortunately, this approach is flawed.
The improvement of the project is by all chances NOT a linear change. You won’t have a change in the system already on the first day (or week or month) of the project. It takes time to get things going. This is especially true if you don’t just do something, but instead follow practical problem-solving and do this in a structured way. At Toyota, the largest part of improvements using the PDCA (Plan, Do, Check, Act) is the “Plan” part. This can easily take more than half of the time for the project. You need time to 1) Clarify the Problem, 2) Break Down the Problem, 3) Set a Target, and 4) Do a Root-Cause Analysis before you eventually develop a countermeasure and implement. For more on practical problem-solving see my series on the Toyota Practical Problem Solving (PPS).
A common mistake in many Western companies is to rush to a solution and to implement anything just to get something done, instead of first thoroughly understanding the problem. I often like to illustrate this using the PDCA cycle as shown below.

Even if you may know right away what the problem is, it sometimes takes time to implement. For example, if you have a technical change with a machine, you may have to order parts, or even a completely new machine or system. As long as the machine is not yet here, you will not see any improvement. Yet, a gradual changing target progression line would put the target in the red, even though everything is progressing nicely. A good improvement project would be labeled red, or behind, even though everything is fine. This muddles the message, and makes it harder to focus on the projects that actually need help and are in trouble.
Hence, for the target progression a linear increase is usually not a good approach, even though it is the easiest. Instead, a step function is often a much better representation of what the project should achieve. For some larger projects it may be even multiple steps. This makes the target setting a bit more difficult, and you have to think more about when the target should move to the next step. This is an additional effort, but as a result the bowler chart will not show you projects in the red even though they are all fine.
Target Met or Not?
This brings me to my last caveat: Are you on target or not? The bowler chart example here shows only red or green. Either you are on target or better, or you are not. Many companies, on the other hand, also use yellow as a color for an intermediate situation.
Red and green are clear, but I have to talk a bit more about yellow. Some companies prefer to use only red and green, and avoid using yellow. A yellow signal could leave some wiggle room and be seen as “almost green.” But here you have to ask yourself, is “nearly good enough” good enough for you? Is an excuse like “it’s not that bad, we are almost there” acceptable? If so, feel free to continue to use yellow too. Albeit, then you would have to define what is acceptable as “yellow.” In its extreme, this would mean another sub-line in the bowler chart for “Almost Good Enough,” as (sarcastically) illustrated below.
Overall, it may be just so much easier to simply use only red and green, and avoid the weasel-your-way-out yellow color. But then, such a yellow is also often well established in many companies, and fighting the system may not be worth it. You decide.
Could the Bolwer Chart Be Improved?
Hence, overall the bowler chart is a way to track the performance of improvement projects. But personally, I think this could be improved. Data tables may be nice and good, but I much rather prefer a more visual representation to make the numbers stick out better. This is now about visual management. Hence, I would try to make it into a diagram. For example, let’s take a look at the quality improvement from our bowler chart example. You could show it as a table or as a diagram. I find the diagram much easier and quicker to read.
Or here is the monthly production quantity project, again as a table (excerpt) and a diagram. For example, the jump in the target between May and June is very visible in the diagram. On the other hand, you may miss it in the table if you are not careful.
You may even have targets that have both a minimum and a maximum value. For example, assume you are trying to reduce temperature fluctuations in your annealing process, and want to reduce the permitted fluctuations from a range of 700 to 800°C to a range of 730 to 770°C. A table now becomes rather complex, whereas a graph is still easy to understand.
While using a diagram instead of a table makes the data more visible and easier to understand, it also does need some additional space. One more reason to limit the number of projects you have ongoing simultaneously. And, as always, it really helps if the project managers write down their data by hand instead of just looking at an auto-generated chart.
This concludes my two-post series on bowler charts. As always, I hope this was helpful to you. Now, go out, track your improvements (or your bowling game), and Organize your Industry!
P.S.: Many thanks to Bernd Sägmüller from Jenoptik for his inspiration and knowledge.
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Vielen DANK für die tollen Beiträge. Ich lese nun schon seit geraumer Zeit diese Berichte und fühle mich immer wieder sehr gut informiert. Zusätzlich bringen mich die Beiträge sehr oft dazu wieder in Aktion zu gehen. Was gibt es überzeugenderes als Taten.
Fantastic article, Christoph! Thanks for sharing! This article really hit home with me. I particularly like the PDCA graphs to show the difference in application of the process between Toyota and Western companies. Unfortunately, I’ve also been involved in projects where the bowler did not accurately account for the ‘plan’ phase of the project, therefore, for the first 4 months, we were ‘losing money’ on the improvement. Ugh!
Regarding PDCA cycle. There are different understandings of what the words actually mean …what goes under those headings. It is tempting to call them mis-understanding, but different organisations may have their own standard, and if it works for them, that’s fine.