Title: Chapter 16 Introduction
Course: Canvas Practice Course > Section: Week 3, 06 April to 09 April

KEY CONCEPTS

Variation in repetitive operations follows discernible patterns and obeys laws of probability that are predictable. The discovery, identification, and use of these basic variation patterns are a main concern of statistical quality control (SQC). The object of SQC effort is to reduce to optimum levels non-random variation, and to assess and control acceptable random variation.

Variation is a tool that can be used to reduce waste and improve a process. Variation is inevitable because of random fluctuations and inconsistencies in (1) machines, (2) materials, (3) manpower, (4) and methods. No two products, batches, or lots produced are exactly alike. The goal of SQC is to find out which variations are due to natural random fluctuations and which variations have an abnormal cause that can be eliminated. When variation is random and stable, the process is in a state of statistical control. A stable process can be kept consistently stable with control charts.