If you have a serious problem, it’s critical to explore everything that might cause it, before you start thinking about solutions. Ishikawa, or cause-effect analysis, is a brilliant tool for doing just this.
Cause and effect
Most of us assume that the relationship between cause and effect is both simple and direct as in the diagram below! However, with just a little bit of thought we can easily see it really ain’t that simple.
In order to properly understand our world, this direct cause-effect model is far too simplistic: day to day reality is far more complex.
Interestingly, I think, management by objectives suffers from this oversimplification. As most of us would expect (and even desire), objectives set in marketing have an effect in sales and operations, objectives set in sales have an effect in operations and service departments and so on. However, when managing staff by objectives, we tend to try and constrain the objectives set for staff in our particular domain and ignore the knock-on implications elsewhere. Madness. We need to think in terms of “systems” (but that’s the subject of a different blog).
Another problem is that the impact of objectives on other people and departments may be small at first and accumulate later. So, in day-to-day reality, the time frames of objectives also need to be considered, and that’s without considering a whole raft of feedback loops that might result.
This leads to a more realistic picture of the relationship between cause and effect as shown in the diagram below.
It is, therefore, not unrealistic to assume that your own business processes will be subject to dozens, or even hundreds, of cause-effect relationships. However, our culture and, particularly, our management training have led us to the belief that, when confronted with a problem, we need to blame someone – some of us even blame ourselves. But, as we can now clearly see, invariably it is “the system” that is more likely to be the problem. Dr Joseph Juran suggested that 85% of the time the problem will be in the system and only 15% of the time will it be the worker. Dr W. Edwards Deming, perhaps in a bid to outdo Juran, wrote in The New Economics:
“In my experience, most troubles and most possibilities for improvement add up to proportions something like this: 94% belong to the system (the responsibility of management) and 6% are attributable to special causes”.
Additionally, as was so elegantly stated by the Hopper brothers in their excellent book The Puritan Gift: Reclaiming the American Dream amidst Global Financial Chaos:
“In any well-run organisation, an individual’s achievements were likely to be due as much to the wisdom with which he was directed from above, and to the support of his equals and subordinates, as to his own efforts”.
This oversimplification of cause and effect is critical because it has a significant effect on how we perceive both variation (the subject of a different blog) and problems.
The cause effect diagram
I originally learnt about Ishikawa diagrams (also sometimes called fishbone diagrams or herringbone diagrams) whilst studying for my engineering degree. The idea was developed by a guy in Japan called Kaoru Ishikawa, who was working, at the time, in the Kawasaki shipyards. He developed the diagrams in order to show the causes of specific events. I initially learnt the 5M model where the head of the fish described the problem, and the bones of the fish bone were indicative of one of the following issues:
- Machine (equipment, technology)
- Method (process)
- Material (includes raw material, consumables, and information)
- Man / mind power (physical or knowledge work)
- Measurement / medium (inspection, environment)
However, as ever, over the years the model has been developed, originally, to include an additional three M’s creating the 8 M model, the additional 3 M’s being:
- Mission / mother nature (purpose, environment)
- Management / money power (leadership)
- Maintenance
Also, as I’ve said many times before in these blogs, these tools should never be about slavish adherence to the tool – they should be about using (and abusing, if necessary) the tool to drive thinking, so we, and others, have used the model with for instance the 8 Ps of the marketing mix.
- Product (or service)
- Price
- Promotion
- Place
- Process
- People (personnel)
- Physical evidence
- Performance
An example
Alternatively, as in the example we are going to use, we have jettisoned the original models and gone for something completely different. In our example, the problem we’ll be concentrating on is:
- “The difference that makes the difference between the performance of different telesales operatives”.
In order to generate this diagram, the sources of variation were brainstormed and the following five arms for the cause-effect diagram were created:
- External factors
- System and support
- Individual factors
- Marketing factors
- Recruitment and training
Further work was then undertaken on each of these to establish lower-level causes that might affect the performance of individual operatives.
There are over sixty items on the diagram and only nine over which the individual has any control. One of these is planning and preparation which, it could be argued, has as much to do with the training provided by the organisation. As a result, we can now see that “the system” (the environment within which the work is undertaken and the way in which work is designed and managed) has a far bigger influence over variation in performance than the individual.
This in itself gives a lie to the myth that in most cases the “individual” is to blame, when in actual fact in most instances it is in fact “the system” and responsibility for changing the system lies with the management!
How to use it
Given you want to use the Ishikawa approach in your own organisation to look at a particular issue, I’d gather a team together and then work through the following four step process.
Step 1: Identify the problem
First, write down the problem you face as concisely and succinctly as possible. You might also identify who is involved and when and where it occurs.
Then, write the problem in a box on the left-hand side of a white board, large sheet of paper, or even specialist software packages these days, and draw a line back across the paper horizontally from the problem box. This arrangement, looking like the head and spine of a fish, provides the space in which to develop ideas.
Step 2: Identify the big issues
Next, brainstorm the key factors, the big issues, that feed into the problem. These may be systems, equipment, materials, external forces, people involved with the problem, and so on. You can use any of the models above, or invent your own
Then draw a line off the “spine” of the diagram for each of the issues you have identified.
Step 3: Identify possible causes
Essentially, repeat the above step for each of the factors you considered, brainstorm the possible causes for each and show these possible causes as shorter lines coming off the “bones” of the diagram. When a cause is large or complex, then it may be best to break it down into further sub-causes and show these as lines coming off each cause line.
Step 4: Analyse your diagram
By this stage you should have a diagram showing all of the possible causes of the problem that you can think of. You should have a complete overall picture with all the necessary granularity in each of the bones.
Depending on the complexity and importance of the problem, you can now investigate the most likely causes further. This may involve other tools 5 Why and 8D, it may also involve setting up investigations, conducting surveys, and so on.
Adding quantitative insight
From time to time, we have also added additional insight by “quantifying” the results obtained. This isn’t a scientific quantification, more a “gut feel” attempt at where we think the big issues lie. At which point we ask and score or rate the following questions:
Question 1) How likely is this cause to be the major source of the issue or problem?
- 5 or V = Very Likely
- 3 or S = Somewhat Likely
- 1 or N = Not Likely
Question 2) How easy would it be to fix or control?
- 5 or V = Very Easy
- 3 or S = Somewhat Easy
- 1 or N = Not Easy
This provides the opportunity to easily prioritise issues or ideas by tackling first those ideas that are very likely and very easy working your way through the issues until you come to those issues that are least likely and most difficult.
Conclusion
The Ishikawa diagram, also known as the fishbone and cause effect diagram, was originally developed as a quality control tool, however, as we have seen it can and should, be used in a variety of other ways, for instance, you can use it to:
- Look at root and contributory causes of problems.
- Highlight bottlenecks in your processes.
- Identify where and why processes are not working.
- The above list is not exhaustive!
The approach is particularly useful as it also provides a visual representation of the causes of a specific event or problem, making it easier to identify root and contributory causes, and indeed, understand the relationships between them.
In short, the Ishikawa approach allows:
- A holistic view of a problem to be created;
- Complex problems to be broken down into smaller more manageable components;
- A systematic investigation of the issues;
- A means of assessing the most likely causes of the problem.
In our view, a great little tool!
Related tools and ideas
Recommended references
- Dragon Slaying – A better way to manage – Mark Woods.
- This shows how Ishikawa is used in conjunction with an understanding of variation
Downloads
- None
