Quality management and operations research

Quality is fitness for use: meeting customer requirements reliably, not gold-plating beyond them. Total quality management (TQM) makes quality everyone's job through customer focus, continuous improvement, employee involvement and fact-based decisions. Statistical quality control (SQC) monitors processes with data: control charts separate common-cause variation (random, built into the process) from special-cause variation (assignable to a specific fault). Worked example: a filling machine's weights vary slightly every time (common cause, acceptable) but suddenly jump high for an hour (special cause — a jammed valve, fixable). Control charts catch the jump before it becomes a batch of rejects. Operations research (OR) complements quality with mathematical decision tools: transportation, queuing, decision theory and PERT/CPM.