The goal of an in-process monitoring solution is to measure the process's performance, the product's quality, or both in a real- or near-real-time manner. An in-process monitoring solution should not be regarded as a replacement for post-process, non-destructive examination. Although this can sometimes occur, an in-process monitoring solution can significantly reduce the over-reliance on post-process inspection by transforming it into a value-added step in the manufacturing effort.
An in-process monitoring solution can serve as the first line of inspection categorizing parts as, for example, either "acceptable", "unacceptable", or "suspect". The "acceptable" parts move on to the next stage of manufacturing, while the "suspect" parts are inspected further using traditional NDE techniques. This "inspect-for-cause" methodology can greatly increase throughput and reduce unnecessary post-process inspection. Furthermore, product quality is immediately identified during or immediately after the process is complete. Troubleshooting an "out-of-control" process can therefore proceed immediately rather than hours or days later when (or if) the non-conformance is detected.
In-process monitoring can minimize machine downtime, reduce scrap, increase throughput, eliminate non-value-added operations, and enhance safety. For a manufacturing environment that is constantly concerned with its "bottom line", the impact of in-process monitoring can be significant. For mission-critical and safety-class-rated (i.e., where product safety is paramount) manufacturing operations, an in-process monitoring solution can provide the quantitative feedback necessary to maintain confidence in product quality. In general, in-process monitoring provides the process engineer with the knowledge that his/her process is "under control".