iSixSigma introduced a good method on finding the root cause of a problem by using 5 why. By repeatedly asking the question “Why” on an issue, you can dig into the root of the cause of a problem. Another good benefit of using this method is that you can determine the relationship between different root causes of a problem. Here is one good example of using 5 Whys:
Problem Statement: Customers are unhappy because they are being shipped products that don’t meet their specifications.
1. Why are customers being shipped bad products?
– Because manufacturing built the products to a specification that is different from what the customer and the sales person agreed to.
2. Why did manufacturing build the products to a different specification than that of sales?
– Because the sales person expedites work on the shop floor by calling the head of manufacturing directly to begin work. An error happened when the specifications were being communicated or written down.
3. Why does the sales person call the head of manufacturing directly to start work instead of following the procedure established in the company?
– Because the “start work” form requires the sales director’s approval before work can begin and slows the manufacturing process (or stops it when the director is out of the office).
4. Why does the form contain an approval for the sales director?
– Because the sales director needs to be continually updated on sales for discussions with the CEO.
In this case only four Whys were required to find out that a non-value added signature authority is helping to cause a process breakdown.
Determine The Root Cause: 5 Whys – [iSixSigma]