and continuous improvement approaches.  Numerous books were written on the subject, including Nakajima's authoritative introduction, and a more recent update by Peter Willmott. Total Quality Management (TQM) A multifaceted, company-wide approach to improving all aspects of quality and customer satisfaction-including fast response and service, as well as product quality. TQM begins with top management and diffuses responsibility to all employees and managers who can have an impact on quality and customer satisfaction. It uses a variety of quality tools such as QFD, Taguchi methods, SPC, corrective-action response teams, cause-and-effect analysis, problem-solving methodologies, and fail-safe-ing (or "poka-yoke" methods). Total Time All time during the period being measured (at the rate of 24 hours per day, seven days per week.) Also equal to the sum of time spent in all six equipment time categories. Tribology The science and technology of interacting surfaces in relative motion and related practices. Friction, lubrication, and wear sciences and technology (American Society of Engineers). True Downtime Cost (TDC) A method of recording and analyzing all significant cost metrics associated with equipment downtime in a building or manufacturing facility. TDC provides a way to assign time and/or monetary value to previously considered "non-tangible" cost of downtime. Also TDC includes downtime factors commonly overlook to arrive at a more true value for the cost of downtime. Turnaround A stop, or full or substantial interruption of plant production.  Generally turnaround is considered to be a period longer than 24 hours. Ultrasonic Inspection A high frequency signal is sent and reflected