Senior executives and machine operators will obviously be looking for very different things when they look to SPC analysis, and systems have to respond to these differing needs. Information has to be presented in such a way as to empower the recipient to improve the process. One area this is especially true is on the manufacturing floor itself. One of the main selling points of many automation systems is the increased knowledge and control they offer to management, but on-line SPC offers something different according to its proponents. You just have to give them the tools to do the job.
Quality is all about data being available at the time work is done.
Which is why in addition to the potential savings in labor, inventory, scrap and returned goods, on-line SPC vendors even tout the potential of their software to improve employee morale. But quality is probably not all about the time of work. By analyzing data over the longer term, managers can begin to make decisions on a number of broader issues affecting product quality, such as operator training, which suppliers to choose, or how raw material ought to be handled prior to production. These correlations between outcome and input are generally accomplished through well-established statistical methods such as linear regression. Where on-line SPC focuses on ensuring critical limits are maintained and that significant trends are recognized and addressed, SQC offers the capability of discovering new critical limits and new factors affecting quality.