Quality management ensures that an organization, product or service consistently functions well. It has four main components: quality planning, quality assurance, quality control and quality improvement. Quality management is focused not only on product and service quality, but also on the means to achieve it. Quality management, therefore, uses quality assurance and control of processes as well as products to achieve more consistent quality. Quality control is also part of quality management. What a customer wants and is willing to pay for it, determines quality. It is a written or unwritten commitment to a known or unknown consumer in the market. Quality can be defined as how well the product performs its intended function.