Quality Improvement Programmes (Metrology)

1.23.
Implementation of quality improvement programmes results into:
— dramatic reduction of defects
— improvement in overall product reliability
— dramatic decrease in the cost of quality
— increased customer satisfaction
— increased overall market share.
The philosophy behind quality improvement program is depicted by following:
— Quality is free since it pays for itself through reduced operating costs and increased sales
through satisfied customers.
— Defect free products are possible and must be achieved. Acceptable Quality Levels
(AQL’s) are no longer good enough.
— Prevention is better than inspection i.e. quality must be built in and not inspected in.
This is possible by eliminating operation and process variables.
— Everyone is a link in the quality chain, i.e. total employee involvement is essential, and
teamwork is the basis of success.
— The concept of Total Business Quality (i.e. only a quality business can deliver a quality
product) need to perculate throughout the plant. A total quality approach to the whole
business is the best strategy.
The sequence of developments in regards of present status of metrology in regard to Quality
is as under:
— Conventional inspection—sorting good from bad after manufacture. This is now a totally
outmoded and inefficient philosophy and practice.
— Operator quality control—A technique in which operator is responsible for the quality
he produces by provision of measurement/gauging equipment with the aim of determin-
ing trends and thus preventing defects from occurring.
— Accuracy capability studies on production machinery—An implicit acceptance, if not full
recognition of deterministic performace of production machines leading to selection of
“accuracy capable” machines and probable use of statistical sampling techniques (SQO.
— Post process measurement, analysis, and feedback control—It is frequently based on
strictly sequential measurement of parts (from which patterns of performance can more
readily be recognised).
— In process measurement and control—In it the speed of response of the closed-loop error
feed back servo-system is at its highest.
— Adaptive control—It can compensate for relatively rapid trends/parameter changes like
grinding wheel wear.