A METHOD OF RATING MANUFACTURED PRODUCT 353 



The rating method recognizes such gradations in seriousness by making 

 use of a system of weighting defects. 



Method of Weighting Defects 



The seriousness of a defect is judged from the standpoint of the 

 consumer. A defect, if allowed to get into service, means trouble in 

 one form or another, and trouble costs money. Seriousness depends 

 fundamentally upon the evaluation of the loss or expense that would 

 be incurred by using the defective unit. The determination of exact 

 costs of trouble is generally not possible but these costs or, better, the 

 relative costs can be estimated. Such estimates may be based on past 

 experience, judgment, engineering knowledge of service requirements, 

 complaints received from consumers and available information on costs 

 associated with past troubles in service. 



A standard set of classes is adopted for defects associated with a 

 given kind of product, the classes being ordered in seriousness and each 

 sufficiently well defined to make the business of classification a fairly 

 simple and uniform process. The following four-fold classification has 

 been found satisfactory for many kinds of telephone products. 



Class "^" Defects — ^Very serious. 



Will render unit totally unfit for service. 



Will surely cause operating failure of the unit in service 

 which cannot be readily corrected on the job, e.g. open 

 induction coil, transmitter without carbon, etc. 



Liable to cause personal injury or property damage. 



Class "jB" Defects — Serious. 



Will probably, but not surely, cause Class "A" operating 

 failure of the unit in service. 



Will surely cause trouble of a nature less serious than 

 Class "A" operating failure, e.g. adjustment failure, opera- 

 tion below standard, etc. 



Will surely cause increased maintenance or decreased life. 



Class "C" Defects — Moderately serious. 



Will possibly cause operating failure of the unit in service. 

 Likely to cause trouble of a nature less serious than operat- 

 ing failure. 



Likely to cause increased maintenance or decreased life. 

 Major defects of appearance, finish or workmanship. 



Class "P" Defects — Not serious. 



Will not cause operating failure of the unit in service. 

 Minor defects of appearance, finish or workmanship. 



It should be pointed out that the number of classes to be used is 

 arbitrary. Two classes, major and minor, may be sufficient for some 

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