Two important charts in SPC are Control Charts and Process Capability Histogram.
Control Charts are used to detect if a manufacturing process is showing symptoms of being influenced by abnormal factors (special causes) which may lead to mass production of out of specification items (non-conformities).
Process Capability Histogram is used to study and optimize process to ensure the most optimum process (machine) set up is achieved for minimum product quality problems.
Unfortunately, many SPC practitioners are using Control Charts incorrectly. As a result, they do not reap any benefits from their SPC implementation after all the effort, money and time spent doing it. Even by having a world class SPC software is useless if the basic of SPC is not rightly understood. A truly knowledgeable SPC trainer or SPC software implementer is crucial to avoid such a situation.
Although there are many type of control charts including those involving very sophisticated and advanced techniques, X-MR & X-Bar R Control Charts are adequate to start with in most Malaysian manufacturing process scenarios.
Plotting Control Charts and Process Capability Histogram manually is time consuming, laboriousness and error prone due to the fact that it involves a lot of data and tedious statistical calculations & result interpretation. A good real-time SPC software will help to plot data captured from measuring devices or equipment into Control Charts and Process Capability Histogram instantly. Any SPC rules violation (out of control occurrences) can be detected and alerted timely to machine operators, engineers etc via monitor, tower-light and email.