18.10.
It is a common experience that management controllable defects greatly outnumber operator controllable defects. According to Dr. J.M. Juran, about 8% of the defects are management controllable and this does not vary from industry to industry, but varies greatly among operations.
Lack of awareness on the part of many industrial managers regarding the fact that the bulk of defects are management controllable compels them to believe that most defects are the
result of operator carelessness, indifference and even sabotage. This leads to embarking on operator motivational schemes.
18.10.1.
Dominant System.
In all processes the input materials are subjected to wide assortment of operational “Systems” (machines, tools, operators etc.) in order to achieve the desired end result. These operational systems are subject to variation, and it is regulation of these variables which is the basic problem of process control. Although the process systems are numerous, it is common to find that one of them “dominates” i.e., it is more important than all the rest put together. It is most helpful to identify the dominant system.
Four of the most useful/usual dominant systems are :
(a) Set-up dominant System : The process has been engineered to so high a degree of reproducibility that, if properly set up in the first time, it will run the entire lot off successfully. Quality in such cases depends on the validity of the original set up of the machine.
(b) Machine Dominant System : The process keeps changing during the fabrication of the lot, requiring periodic check and readjustment.
(c) Operator Dominant System : The operation has not been fully engineered and the unengineered residue, which depends on the skill and attention of the operator, is the major cause of defectives.
(d) Component Dominant System : The input materials or components are the main variables affecting the Quality of the finished product.
The dominant system is not the sole source of defects for the process in question, but it is the main source ; e.g. a printing operation is set up dominated as to defect such as spelling or colour of ink. It is operator dominated as to the finger prints on the sheet.
If the operator controllable defects predominate, the Quality Improvement Programme must be designed to influence a large number of people to CHANGE THEIR ATTITUDE TOWARDS QUALITY. If the management controllable defects predominate, then the programme must be designed to DIAGNOSE THE CAUSE FOR THE DEFECTS AND TO DEVELOP REMEDIES.
18.10.2.
Quality Improvement.
Sporadic Troubles—Trouble Shooting. All continuing performances are subject to variation. Some of these variations are non-significant and are ignored or deferred as to corrective action. Other variations are so significant that they trigger the alarm signals of the control systems. Significance may be either statistical or economic or both. For a discussion of statistical significance, statistical tests are applied. Economic significance is influential in establishing the order of priority of corrective actions to be taken. These significant variations are a form of sporadic departure from standard which call for quick diagnosis of the cause and removal of the cause to restore status quo. The sequence of events used to RESTORE THE STATUS QUO is known as trouble shooting or fire-fighting.
Chronic Trouble : Break Through
There are cases in which the same problem comes up over and over again, suggesting that the cause is not a reported error but a basic deficiency in the design, process system etc. Such problems are usually major and cause only minor irritations (as its continuous nature leads all concerned to accept it as unavoidable). The solution calls for extensive and complex data collection over long periods, analysis of data by technical and SQC personnel using SQC techniques. The solution when implemented CHANGES THE STATUS QUO and a new level of performance that is superior to the previous level is achieved.
Thus the two essential criteria for “Break Through” are ;
(a) The new (superior) level of performance has never previously been attained. IT SETS A NEW RECORD.
(b) The change is the result of human determination to set a new record. It is not the result of luck.
MAN, NOT CHANCE, IS THE MASTER.
