Material problems, machine vibration is too large, the excessive wear of the tool, fixture seriously loose workers violated rules, test errors and so on. These factors can cause quality problems of wall switch, then under certain conditions, from the techniques above can be eliminated, cost calculation, manufacturers are also cost-effective. Therefore, these quality problems, can be avoided completely. Typically, quality problems caused by our material under normal conditions is called the normal fluctuations, and believes that when the production process or the process under control or stable state.
If it was a result of quality problems, we call it abnormal fluctuations. Such situations are often wall switch products or process is in a State of non-controlled or unstable state. Statistical control chart's main role is to: identify quality index value of fluctuation is normal or abnormal, judging process or procedure is under control or non-control v-State.
When wall switch products for production engineering, non-controlled state, then trace the cause and taking measures to eliminate exceptions, wall switch products or in the course of control state, so that the wall switch and the quality of products is guaranteed.