To develop a better understanding of Control Charts and Process Capability, we must start by discussing briefly the five fundamentals concepts for the successful use of Statistical Process Control (SPC), which are:

  1. Nature/Origin of Variations;
  2. Process Evolution (over time);
  3. Shewhart’s Concept of Statistical Control;
  4. Managing Variability Using Control Charts;
  5. Using the Statistical Process Control method.

The ability to embrace the continuous improvement philosophy relies on how well those five concepts above are understood. Process Control equations, tables, graphs and others analytical/numerical representations and summaries may well be misinterpreted and misused without a solid understand of those concepts.