A cost and performance management concept defining methods used to measure costs, plan spending, and analyze deviations from expectations. It governs cost attribution, budgeting, forecasting, and variance drivers used to improve profitability and operational decisions. It does not ensure savings without accurate cost drivers, timely data, and follow-through on corrective actions. It supports operational control by turning spending and output into interpretable measures and actionable insights. The concept is generally stable, though analytics tooling and planning practices evolve over time.