Since the development of statistical process control during the middle of the 20th century, the methods that conventionally fall under the SPC designation have become increasingly sophisticated, and they’re now being applied in countless ways in virtually all segments of business and manufacturing. In fact, if you were to do a survey of the most successful companies in the world, you would undoubtedly find SPC methods being used in some capacity by the vast majority of them. And the fact that SPC can be used in such a wide range of applications shows just how useful it is.
For anyone new to statistical process control, it may be difficult to imagine exactly how these methods can be put into action, so let’s look at a few real-world applications in which SPC is now being used.
Food manufacturing: In most developed countries, there are very strict regulations governing how food can be processed and marketed. In most places, makers of food products are required to print full ingredient lists along with detailed information about the nutritional value of the food. In order to stay true to what’s printed on the label, companies must make sure that the products they make have very little variance from item to item.
That’s where statistical process control comes in. When items begin coming out of the manufacturing process with flaws or variances, the managers simply go to the statistics and look for data points that are out of line with expectations. More often than not, finding the source of the problem is as simple as locating the problematic statistic, tracing its cause, and making small, precise adjustments to the process.
Medical supplies: Statistical process control has proved immensely useful in fields where life and death depend on items being manufactured to precision. Before statistical process control, the manufacturing of medical supplies required huge quality control teams to monitor all stages of the process and test every piece of equipment as it came out of the manufacturing process. Today, while there is still extensive quality control that must be done, statistical process control has made monitoring for and eliminating variances far more efficient. What was once done by a full department in a company can now be done by one or a few individuals.
Vehicle manufacturing: As with medical supplies, vehicles such as cars, trucks, and airplanes, must be manufactured with every element within very specific ranges, or else the safety of the vehicles’ operators and passengers is put at risk. Since Henry Ford pioneered many aspects of the modern assembly line in the early 20th century, the automobile industry has always been at the cutting edge of the world’s manufacturing processes, and the industry’s use of SPC keeps it at the cutting edge even to this day.
The average consumer of motor vehicles doesn’t realize just how complex today’s cars are. A typical vehicle can have upwards of 10,000 parts, and for aircraft this figure might be multiplied a few times. Making sure all these thousands of parts are assembled well and run perfectly requires extensive statistical monitoring. Today, much of the process is automated, but human process control managers still play a large role.
