A defect location check sheet (also known as a defect map or a measles chart) is a structured, prepared form for collecting and analyzing data that provides a visual image of the item being evaluated so that data can be collected visually rather than merely collecting a count of the number of defects.
Use: A common practice in quality assurance or even in six sigma is to count the number of defects found. One could keep track of the defect rate, and maybe even use an attribute chart to monitor, control, and continuously improve upon defect rates. But what is missing is where the defects are located. That is where the defect location check sheet comes in handy. Draw a picture of the product. Then, every time a defect is found, the operator or the inspector puts a mark on the drawing as to where the defect was found. So let’s say that there is a cluster of markings in the upper right-hand corner of the drawing. The six sigma team could look at that defect location check sheet and look up-stream in the process to see if they can identify what in the process is causing a defect to show up in the upper right-hand corner of the products. Again, much of six sigma in lean has to do with visualizing the sources of variation, waste, or defects.