Total Quality Management
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Total Quality Management or TQM
In 1984, the United States Department of the Navy Personnel Research and Development Center began researching the use of Statistical process control (SPC) and quality management methods for potential benefit in making performance improvements. This work included a detailed examination of the quality management approaches advocated by Philip B. Crosby, W. Edwards Deming, and Joseph Juran.
The result was an approach that combined SPC principles with the philosophy of W. Edwards Deming. This approach was first tested at the North Island Naval Aviation Depot.
The name “Total Quality Management” (TQM) was first used by the Department of the Navy in 1985 when they were starting to introduce the methods that had been successful in the North Island test to other Naval installations.
TQM is considered a management strategy to embed awareness of quality in all organizational processes. TQM is not limited in its application and has been widely used in manufacturing, education, government, service industries, as well as NASA space and science programs.
Quality assurance through statistical methods is a key component in a manufacturing organization where TQM generally starts by sampling a random selection of the product. The sample can then tested for things that matter most to the end users. The causes of any failures are isolated, secondary measures of the production process are designed, and then the causes of the failure are corrected. The statistical distributions of important measurements are tracked. When parts' measures drift into the error band, the process is fixed. The error band is usually tighter than the failure band. The production process is thereby fixed before failing parts can be produced.
It's important to record not just the measurement ranges, but what failures caused them to be chosen. In that way, cheaper fixes can be substituted later, (say, when the product is redesigned), with no loss of quality. After TQM has been in use, it's very common for parts to be redesigned so that critical measurements either cease to exist, or become much wider.
It took people a while to develop tests to find emergent problems. One popular test is a "life test" in which the sample product is operated until a part fails. Another popular test is called "shake and bake". The product is mounted on a vibrator in an environmental oven, and operated at progressively more extreme vibration and temperatures until something fails. The failure is then isolated and engineers design an improvement.
A commonly-discovered failure is for the product to come apart. If fasteners fail, the improvements might be to use measured-tension nutdrivers to ensure that screws don't come off, or improved adhesives to ensure that parts remain glued.
If a gearbox wears out first, a typical engineering design improvement might be to substitute a brushless stepper motor for a DC motor with a gearbox. The improvement is that a stepper motor has no brushes or gears to wear out, so it lasts ten times or more longer. The stepper motor is more expensive than a DC motor, but cheaper than a DC motor combined with a gearbox. The electronics is radically different, but equally expensive. One disadvantage might be that a stepper motor can hum or whine, and usually needs noise-isolating mounts.
Often, a TQMed product is cheaper to produce because of efficiency/performance improvements and because there's no need to repair dead-on-arrival products, which represents an immensely more desirable product.
See also
- Malcolm Baldrige National Quality Award
- European Foundation for Quality Management (EFQM),
- Japanese Union of Scientists and Engineers,
- Management Models and Business models,
- Process improvement
- Reengineering
- Six Sigma
- Statistical process control
External link
- Total Quality Management in Libraries (http://www.michaellorenzen.com/eric/tqm.html)de:Total-Quality-Management