| Total Quality Management or TQM is a management strategy to
embed awareness of quality in all organizational processes. Quality assurance through statistical methods is a key component. TQM aims to do things right the first time,
rather than need to fix problems after they emerge or fester. TQM may operate within quality circles, which encourage the
meeting of minds of the workforce in different departments in order to improve production and reduce wastage.
In a manufacturing organization, TQM generally starts by sampling a random selection of the product. The sample is then tested
for things that matter to the real customers. 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 out of 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 there's no need to repair dead-on-arrival products), and can yield
an immensely more desirable product.
TQM can be applied to services (such as mortgage issue or insurance underwriting), or even normal business paperwork.
TQM is not a focused improvement approach. The customer desires and product tests
select what to fix. Theoretical constraints are not considered at all.
Evaluation of TQM
It is important to note that TQM is discredited in the eyes of some people, and is suffering somewhat of a backlash after its
peak of popularity in the late 1980s and early 1990s.
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