More and more companies have implemented quality management in their operations. According to isixsigma.com, many international organizations have implemented total quality management (TQM) such as Toyota Motor, Motorola, Ford Motor, and Philip semiconductor. TQM which is a strategy aimed at embedding awareness of quality in all organizational process (wikipedia) began in the 1950’s and it has become widely known in 1980’s. Also, Six Sigma was originated from Motorola in 1986. Its purpose is to “identify and remove the causes of defects and errors in manufacturing and business processes. It uses a set of quality management methods, including statistical methods, and creates a special infrastructure of people within the organization” (wikipedia). Another system, Just in Time (JIT) is used to manage inventory effectively and increase the return on investment. Just in Time is first applied by Ford Company in 1923, and then it was implemented by Toyota Motor. Applications of these strategies and techniques have provided many benefits for a company. Beasley states that some of the benefits of JIT are: cost savings, higher productivity, reduce scrap and rework. Wilson also mentions that TQM helps reduction in variation, and supplier integration. In discussing Six Sigma, Waxer lists some of the benefits of Six Sigma as cost avoidance, additional revenue, and increase in productivity. Thus, the practices of TQM, JIT, and Six Sigma have impacts to each other.
In this article, we will summarize the concepts of total quality management, Six Sigma, and Just in Time. At the same time, we will discuss the relationships of these topics.
2.Definition of TQM, JIT, and Six Sigma
In the book–Introduction to operations and supply chain management, Bozarth & Handfield (2006, p. 77) define Total Quality Management (TQM) as a comprehensive and managerial approach in which the organizational is managed so that it excels in all quality dimensions that are important to customers. This philosophy is originated in the 1950's by Deming and has steadily become more popular since the early 1980's. There are seven key principles in TQM such as customer focus, leadership involvement, continuous improvement (Kaizen), employee empowerment, quality assurance, supplier partnerships and strategic quality plan.
TQM processes are divided into four sequential categories: plan, do, check, and act (the PDCA cycle). In the planning phase, people define the problem to be addressed, collect relevant data, and figure out the problem's root cause; in the doing phase, people develop and implement a solution, and measure its effectiveness; in the checking phase, people confirm the results through before-and-after data comparison; in the acting phase, people document their results, inform others about process changes, and make recommendations for the problem to be addressed in the next PDCA cycle. TQM requirements may be in adherence to established standards, such as the International Organization for Standardization's ISO 9000 series. TQM can be applied to any type of organization from manufacturing sector to almost every type of organization imaginable, including schools, highway maintenance, hotel management, and churches. As a current focus of e-commerce, TQM is based on quality management from the customer's point of view.
Also in this book, Bozarth& Handfield (2006, p. 491) claim that Just-in-time (JIT), invented by Toyota, is a philosophy of manufacturing based on planned elimination of all waste and on continuous improvement of productivity. On the other hand, it is a process by which companies don't keep lots of excess inventory; instead, they try to pull products out of factory based on accurate demand. Thus, this method requires that producers are able to accurately forecast demand. A good example would be a car manufacturer that operates with very low inventory levels, relying on their supply chain to deliver the...