Taguchi Methods: The American Supplier Institute’s trademarked term for the quality engineering methodology developed by Genichi Taguchi. In this engineering approach to quality control, Taguchi calls for off-line quality control, on-line quality control and a system of experimental design to improve quality and reduce costs.
Takt time: The rate of customer demand, takt time is calculated by dividing production time by the quantity of product the customer requires in that time. Takt is the heartbeat of a lean manufacturing system. Also see “cycle time.”
Tampering: Action taken to compensate for variation within the control limits of a stable system; tampering increases rather than decreases variation, as evidenced in the funnel experiment.
Task: A specific, definable activity to perform an assigned piece of work, often finished within a certain time.
Team: A group of individuals organized to work together to accomplish a specific objective.
Technical report (TR): A type of document in the International Organization for Standardization portfolio of deliverables.
Technical specification (TS): A type of document in the International Organization for Standardization portfolio of deliverables.
Theory of constraints (TOC): A lean management philosophy that stresses removal of constraints to increase throughput while decreasing inventory and operating expenses. TOC’s set of tools examines the entire system for continuous improvement. The current reality tree, conflict resolution diagram, future reality tree, prerequisite tree and transition tree are the five tools used in TOC’s ongoing improvement process. Also called constraints management.
3P: The production preparation process is a tool for designing lean manufacturing environments. It is a highly disciplined, standardized model that results in the development of an improved production process in which low waste levels are achieved at low capital cost.
Throughput: The rate the system generates money through sales, or the conversion rate of inventory into shipped product.
TL 9000: A quality management standard for the telecommunications industry based on ISO 9000. Its purpose is to define the requirements for the design, development, production, delivery, installation and maintenance of products and services. Included are cost and performance based measurements that measure reliability and quality performance of the products and services.
Tolerance: The maximum and minimum limit values a product can have and still meet customer requirements.
Top management commitment: Participation of the highest level officials in their organization’s quality improvement efforts. Their participation includes establishing and serving on a quality committee, establishing quality policies and goals, deploying those goals to lower levels of the organization, providing the resources and training lower levels need to achieve the goals, participating in quality improvement teams, reviewing progress organizationwide, recognizing those who have performed well and revising the current reward system to reflect the importance of achieving the quality goals.
Total productive maintenance (TPM): A series of methods, originally pioneered by Nippondenso (a member of the Toyota group), to ensure every machine in a production process is always able to perform its required tasks so production is never interrupted.
Total quality: A strategic integrated system for achieving customer satisfaction that involves all managers and employees and uses quantitative methods to continuously improve an organization’s processes.
Total quality control (TQC): A system that integrates quality development, maintenance and improvement of the parts of an organization. It helps a company economically manufacture its product and deliver its services.
Total quality management (TQM): A term first used to describe a management approach to quality improvement. Since then, TQM has taken on many meanings. Simply put, it is a management approach to long-term success through customer satisfaction. TQM is based on all members of an organization participating in improving processes, products, services and the culture in which they work. The methods for implementing this approach are found in the teachings of such quality leaders as Philip B. Crosby, W. Edwards Deming, Armand V. Feigenbaum, Kaoru Ishikawa and Joseph M. Juran.
Toyota production system (TPS): The production system developed by Toyota Motor Corp. to provide best quality, lowest cost and shortest lead time through eliminating waste. TPS is based on two pillars: just-in-time and jidohka (see listings). TPS is maintained and improved through iterations of standardized work and kaizen (see listing.)
Transaction data: The finite data pertaining to a given event occurring in a process. Examples are the data obtained when an individual checks out groceries (the grocery shopping process) and the data obtained from testing a machined component (the final product inspection step of the production process).
Tree diagram: A management tool that depicts the hierarchy of tasks and subtasks needed to complete an objective. The finished diagram bears a resemblance to a tree.
Trend: The graphical representation of a variable’s tendency, over time, to increase, decrease or remain unchanged.
Trend control chart: A control chart in which the deviation of the subgroup average, X-bar, from an expected trend in the process level is used to evaluate the stability of a process.
TRIZ: A Russian acronym for a theory of innovative problem solving.
T-test: A method to assess whether the means of two groups are statistically different from each other.
Type I error: An incorrect decision to reject something (such as a statistical hypothesis or a lot of products) when it is acceptable.
Type II error: An incorrect decision to accept something when it is unacceptable.