Determining process capability often involves calculating a metric representing its performance in terms of standard deviations from a desired target. This involves defining defect opportunities, collecting data on defects or deviations, calculating the defect rate (DPMO – Defects Per Million Opportunities), and then converting this to a sigma value using a standard conversion table or statistical software. For example, a process with a DPMO of 3.4 corresponds to a six sigma level.
Understanding process capability provides valuable insights into efficiency, predictability, and customer satisfaction. By quantifying performance variations, organizations can identify areas needing improvement, prioritize resources effectively, and make data-driven decisions for process optimization. This approach, initially popularized by Motorola in the 1980s, has become a cornerstone of quality management across various industries.