Using Cause-and-Effect Diagrams:  Getting to the Real Issues

As a leader, you will undoubtedly spend a fair amount of time anticipating and solving problems.  Some problems have simple solutions, while others require more in-depth analysis.  It's possible to misidentify a problem, thinking it's one thing when it's actually just a symptom of a larger issue. To help us better understand and solve problems, we have a tool called the cause-and-effect diagram.

The cause-and-effect diagram was created by Dr. Kaoru Ishikawa in the 1960s to help improve quality control processes in shipbuilding. You may know it as the fishbone diagram or Ishikawa diagram.

This tool helps us visually see the possible causes of a problem and helps organize related issues into categories to better define the problem.

To use this tool, we first need to know the meanings of the words "cause" and "effect." The cause is the reason why something happened. For example, if you get a speeding ticket, the cause is that you were driving above the speed limit, and a police officer happened to measure your speed with a radar gun. The effect is what happened, which, in this case, is getting a speeding ticket.

It's essential to understand that a problem can have multiple causes, meaning there could be several reasons for a particular effect or issue. The cause-and-effect diagram helps us identify these causes systematically. By doing so, we can focus our efforts on addressing the root causes of a problem, rather than just the symptoms.

Let’s look at an example of poor quality in a software product (the effect). There are multiple causes that contribute to this problem.   Below is an example of a fishbone diagram that was developed to determine why the quality of a software product was low.   

Steps followed to create this diagram.

Step 1:  Define the Problem.  Defining a problem might seem easy at first, but it can be more complicated than it appears. Sometimes, we rely too much on our past experiences and jump to conclusions, thinking we know what the problem is. However, this can lead to misidentifying the problem and only treating its symptoms. For example, someone may say that there are too many application errors, but that could just be one factor contributing to the larger issue of poor product quality.
To develop an accurate problem statement, take the time to identify the real problem, not just the contributing factors. Defining the problem accurately is crucial to finding the root cause and addressing it effectively.
The Problem Statement becomes the “head” of the fishbone diagram. In the diagram above, this is Product Quality.

Step 2:  Develop the Cause Categories.  The categories of the cause of the problem in the example above are Tools, Methods/Process, Materials, and People.  Other categories may include environment, skills, external forces, equipment, and control.  For marketing, the categories may include product, place, price, and promotion.  Brainstorm four to six categories that most of the causes would fall under.  List the categories as branches from the main line.

Step 3:  Document Possible Causes.  Brainstorm the various possible causes that contribute to the problem statement, listing each of them under the appropriate category(s).  In some cases, one cause may fall under more than one category – list it under all that apply.  

Step 4:  Ask Why.  Continue to ask “Why does this happen?” for each cause to continue drilling down to the root causes.  We call it the two-year-old line of questioning:  Why do I have to eat vegetables?  Why do I want to grow up to be big and strong?  Why is that important?  Why…  

Step 5:  Analyze the Causes.  After listing all possible causes, it's time to analyze the diagram as a group. Look for patterns and causes that appear more than once. You'll probably notice several common themes that come up. This is an important part of the exercise because identifying these patterns can help pinpoint the root cause of the problem.

Step 6:  Prioritize.  Now that you've analyzed the diagram to identify the root cause of the problem, it's time to prioritize how to address the issues. Look at the diagram and figure out which areas can be fixed easily to take advantage of "low-hanging fruit". Also, consider which causes have the biggest impact on the problem. By doing this, you can determine which issues need to be tackled first and which ones can wait. This helps you make the most effective use of your time and resources to address the problem.

Based on the example above, which would you prioritize?

If you want to improve your problem-solving skills and become a more effective leader, add the cause-and-effect diagram to your leadership toolbox. This powerful tool is often overlooked in many companies, but it can help you tackle even the most complex problems.

By visually representing the causes of a problem, you can identify the root cause and develop a plan of action to address it.  Take the first step and start using the cause-and-effect diagram as a regular part of your leadership toolkit.

Problem-solving is covered in detail in the Engineering to Executive™ training.  Contact us to learn more!