All entries for Sunday 09 December 2012
December 09, 2012
Which tool to use to identify quality characteristics of the process? And what do you mean by quality characteristics? These are two main questions which I faced during PMA writing.
The quality characteristics are usually a measurement of the process. And SIPOC diagram involves the measurement of the process identification consequently I can use it as a tool. But SIPOC is commonly considered as a tool for describing the process, not identifying how it can be measured. In that point of view SIPOC is not the best choice. Can we then use fishbone diagram logic to identify the characteristics? Fishbone diagram enable to develop those characteristics through 5 factors: methods, materials, people, environment, and equipment. But it usually applied when the need of cause and effect analysis appeared. A good combination of SIPOC and fishbone principles is presented in CTQ tree. Using this tree you focus on customers’ expectations, which can be taken from SIPOC diagram, then for each customer expectation you develop the key characteristics which are essential to satisfy the customer. And this CTQ tree uses the same logic as fishbone diagram – it describes the characteristics by combining them in different groups (drivers). In case with fishbone these are 5 factors.
CTQ tree seems to be most appropriate tool that helps to identify quality characteristics of the process, there are lots of others tools, but CTQ provides a highly descriptive approach with a good visualization.