QUALITY CONTROL CHARTING
Quality control engineers take RANDOM SAMPLES of manufactured items from a production line and inspect for DEFECTS by soe appropriate means. The number of rejects are plotted on a QUALITY CONTROL CHARTS, such as that shown above. The CHART has UPPER and LOWER CONTOL LINES to bound out EXTREME VALUES.

The chart is constructed according to the NORMAL DISTRIBUTION ("bell curve") shown on left side.

  1. Several SAMPLES are taken and rejections noted;
  2. the MEAN NUMBER OF REJECTIONS is computed, determining the CENTER LINE of the CHART;
  3. the STANDARD DEVIATION FROM THE MEAN is computed;
  4. in a NORMAL DISTRIBUTION, 99.73% of all cases fall inside or on 3 STANDARD DEVIATION FROM THE MEAN, which determines the UPPER and LOWER CONTROL LINES of the CHART.
If a REJECTION TOTAL falls above the UPPER CONTROL LINE (estimated probability 0.00135), this is a warning to the engineers that THE PROCESS MAY BE GOING OUT OF CONTROL, and could become worse. They consider ways of bringing the PROCESS back UNDER CONTROL, so that most of the ball bearings will PASS INSPECTION.

If a REJECT TOTAL falls below the LOWER CONTROL LINE (estimated probability 0.00135), the engineers realize that "something good may be happening" -- better supplies, better workmanship, or whatever. They try to find a "cause" and take advantage so that THE QUALITY AVERAGE INCREASES.

By similar methods for various types of equipment, QUALITY CONTROL helped to win WORLD WAR II and enriched the economy and improved our postwar lives.

This is quality-control-by-exception: the engineer does no bother to investigate the production quality EXCEPT when it DEVIATES VERY SIGNIFICANTLY FROM THE AVERAGE. This, in turn, has given rise to tne notion of management-by-exception: set up routines to deal with routine events in a routine away -- only involving the manager with the very EXCEPTIONAL.

This could be turned into security-by-exception: all kinds of data involving the routine life and business of the given person or institution are fed into a computer program, with exceptions to the average being "put on the screen" of the user.

This would also serve for good management, hence, the title on the FRONTPAGE of "MANAGEMENT::SECURITY" for the homology of qchart:management::qchart:security.