Why Why Analysis

Why Why Analysis is a method used for finding out the root cause of a problem or symptom. In this method a series of why questions are asked about the problem. And finally we will reach the root cause of the problem. Why Why Analysis is used for root cause analysis of a problem, which results in problem solving. Root cause can be obtained within 5 why in most problems.

I will explain this with an example.

In an electromagnetic coil manufacturing company there was severe recurring defect. Before explaining about the defect I will explain about the electromagnetic coil.

Electromagnetic coil contains a plastic part called bobbin, two metal parts called terminals which is inserted in to the bobbin by press fitting, copper wire which is wounded over the bobbin and a metal part called core which is inserted in to the hole of bobbin which directly pass through the coil.

The purpose of the electromagnetic coil is to induce magnetic field, through electromagnetic induction, when current pass through the coil.

I hope it’s clear about the product.

Now about the defect.

Copper wire is broken either in the winding operation or at the next stages. This defect is very severe and it will stops the functioning of the coil, since the current cannot pass through the copper wire.

Now we can do the why why analysis for finding the root cause of the defect.

Before starting why why analysis we must investigate how the defect occured.

How the defect occured?

After investigation it is found that the defect occurs at the winding or after winding operation, because this defect is not observed before winding operation. And ofcourse it will not happen. And also it’s observed that the coil breaks near the terminal. And in further investigation sharp edges where observed on the terminal where coils are hooked.

And finally we arrived at the below summary on how the defect occurs.

When the winding machine hooks the copper wire on the terminal with sharp edges, the winding wire breaks due to the force exerted by the sharp edge. The breakage will partial or complete. Partial breakage will completely breaks, when a small force is exerted on the coil in any of the stages after winding.

Now we can do why why analysis.

Why 1

Why the copper wire breaks?

Ans: When the winding machine hooks the copper wire on the terminal with sharp edges, the winding wire breaks due to the force exerted by the sharp edge.

Why 2

Why there is sharp edge on the terminal?

Ans: The insert in the stamping tool, which gives the chamfer to the edges of the terminal is damaged due to wear and tear.

Why 3

Why the insert got damaged?

Ans: Only one lakh terminals can be stamped using that insert and it’s already stamped one lakh fifty thousand terminals.

Why 4

Why the insert is not replaced at one lakh stampings?

The tool maintenance section was not aware about that the that tool has stamped one lakh terminals.

Why 5

Why tool maintenance section was not aware about that the that tool has stamped one lakh terminals?

Ans: Because there was no system to monitor the no of parts stamped by a stamping tool and for it’s preventive maintenance.

I think we are done here. And the root cause of the problem is ‘there is no system to monitor the no of products produced and preventive maintenance’.

So the solution is ‘ to implement a system to monitor the no of products stamped and to do preventive maintenance’.

Only stop the why why analysis if we feel that we have found out the root cause.

How to identify a root cause?

If we feel that, after implementing a solution to a cause of a problem, that problem do not occur anymore, that cause is the root cause.

Generally we say we will arrive at the root cause within asking 5 why questions. But that’s not the case all the the time, it can be go beyond 5 why.

We are lucky we got the root cause at the fifth why.

Hope you got the idea of Why Why analysis.

For arriving at a solution there are different type of methods. Following is one type of thinking which will help to arrive the best solution faster and easily. Also if you like this website and its posts and want to subscribe to this website please click here.

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