Results Measures vs. Process Measures

At this point, we should make an important distinction between these two types of measures.

Results Measures:

• are measures of the overall process performance; they relate solely to some characteristic of the final output
• will indicate whether the process has achieved the required standards
• will not tell you how to improve the process

Process Measures:

• are measures which relate to some characteristic of the process itself
• are indirectly related to the overall process performance
• will indicate where improvement is required in the process

The specifications approach relies on results measures, and thus it only ever tells you how well or how badly you have done. In order to understand how and why your organisation works, and to effect any kind of improvement, it is necessary to change the focus from the outputs to the processes themselves. This is where statistical process control comes in. So what exactly is SPC?