Efficient production requires clear measurements across output, cost, and quality. Plant managers and analysts rely on key performance indicators (KPIs) to spot bottlenecks, control expenses, and ensure high quality. Below are 15 essential metrics for manufacturing flow, divided into Operational Efficiency, Cost Control, and Quality Assurance categories. For each metric we describe what it is, how to calculate it, why it matters, and typical benchmarks or targets in industry practice.