Quality control and quality assurance are procedures to ensure products and services meet defined standards. Quality control ensures manufactured products adhere to quality criteria through procedures like analyzing raw materials and monitoring production processes. Quality assurance sets requirements for services under development. Implementing quality control can increase productivity and profits while reducing costs and increasing customer base through reduced repairs. It involves input, conversion, and output stages of monitoring raw materials, production processes, and finished goods. Quality control guidelines use tools like checklists, control charts, histograms, scatter plots, flow charts, and Ishikawa diagrams to analyze defects.