ABSTRACT
As described in an earlier chapter, process monitoring activities can provide important feedback information that may be used in establishing the quality of a manufacturing operation. This process of monitoring the quality of an operation while products are being manufactured is achieved through the characterization of appropriate system parameters. In order to accomplish this objective, a suitable combination of measurement transducers and data analysis techniques are required. The intent of this procedure is to infer the quality of the manufacturing process through a statistical interpretation of the output from the measurement transducers. (It is assumed that the monitored information has been previously proven to be indicative of the condition of the key process parameters.)
Various measurements transducers have been described in a previous chapter and for simple manufacturing operations it may be possible to monitor these devices using manual methods. However, for more complex monitoring needs, the use of computers is frequently required to pre-process the measurement signal, collect the information in an appropriate fashion and to analyze the resulting data. While this more complicated task could be accomplished using manual methods, the use of the computer permits the completion of the data processing in a timely fashion. This allows the resulting information to be available while the manufactured products are still at a point in the fabrication cycle at which process adjustments can be performed that will result in improved quality. Significant delays in information collection and analysis result in data that describes the condition of the operation for a given batch. While this is valuable information from a historical standpoint, it is of relatively little value for improving the level of real-time quality control.
