Before rushing to solve a problem, every problem solving method recommends to spend meaningful time to analyse, understand and plan the action.
The “is / is not” analysis is a very simple yet powerful tool to help clearing what is in the scope and what is to be left aside.
The principle of “is / is not” analysis is to split a paper board (or any support) in two columns, one for “is” and the other for the “is not”. Consider all data and facts and try to understand what is influencing to the problem and what not.
For instance if the problem is frequent deliveries of non-complying lots to quality standards, following questions may help to sort what is and what is not:
Do we have similar problems with different suppliers?
If not, this supplier may be “in” and will be added in the “is” column. If similar problems happened with different suppliers, the variable “supplier” is to be left out, it “is not” a cause of our problem.
In the same way, the investigation goes on:
- Does it happen with different materials?
- Does it happen a specific day/month/moment?
- Does it happen with different quality control operators?
- Etc.
To go on with questions, do not hesitate to use the 5W2Hs
To me “is / is not” analysis looks like playing mastermind, the game you’ll have to guess a hidden combination by trial-and-error, eliminating step by step what is not relevant/influencing.
Alas, as so often (over)simplistic tools are disregarded despite their power. This kind of analysis is not very often used.
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About the author, Chris HOHMANN
Chris HOHMANN 
Experience with Is/Is Not. (Without disclosing client information). To solve a quality problem with window winder mechanisms at Tier 1 supplier. Problem had been running for some months despite problem solving attempts. Client asked us to work with a team. We decided to try Is/Is Not analysis to help clarify the problem (Toyota Practical problem Solving second step). We actually created it on a giant piece of paper on the floor and used actual parts in the analysis.
The manufacture of these parts was done across shifts working 24/7, on non dedicated stations and equipment.
Using Is/is Not the team discovered that the faulty parts were all made on one particular piece of tooling. This tooling was found to be worn and subsequently this was the root cause of the defect.
The problem was completely eliminated within a week.
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Thank you Christine for your testimony!
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