Question: What is QA/QC in mechanical engineering?
Answer : I will try to give an answer with a simple example.
Suppose your company is producing gear boxes. Then QC of the gear boxes you produced may consist of following:
- test the slip of the gear box by switching from forward to backward rotation
- test the friction of the gear box by measuring the power consumption of a motor connected to the gear box
- insure a minimum stability by fixing one end of the gear box and asserting a strong, but well defined torque at the other end
QA of your gear box is much wider. First you define how you can measure the quality of your gear box. It could be the combined test result of the above three tests for example. Then you go over the entire production process and investigate the influence production parameters of your process on the resulting quality of your product and define measures during the production process, which ensure quality. One measure could be to introduce inspection of the gear wheels of measuring the pressure, when pressing the two side walls of the gear box together.
To wrap it up, quality assurance continuously looks for measures, which help keep or improve the quality of the product. Quality Control just takes the product or any part of it during the production process and checks, whether its quality is sufficient.（Author: Martin Varendorff From: Quora）