When the variability present in a production process is limited to chance variation, the process is said to be in a state of "Statistical Control". The state of statistical control is matted by avoiding of another variation, called as assignable variation. An assignable variation may be due to the extraneous causes like defective maneuvering of the machine, poor quality, raw materials, man-made error and so on. Since assignable variation may contribute substantially to the deviations from the state of statistical control, a systematic method of detecting and eliminating deviations before or during the course of a manufacturing process is desirable. Thus the act of getting a process in statistical control involves the identification and elimination of assignable variation.
A production process is said to be in a state of statistical control if it is governed by chance variations alone and the assignable variations are totally absent in the process. The main objective in any production process is to control the quality of the finished product so that it conforms to specifications.
No comments:
Post a Comment