To ensure design, calibration, production and in process checks deliver a product / service which meets the intended specification first time, every time. This should avoid the requirement for onerous final quality control checks and the associated requirement to return sub-standard issues for costly rectification. The quantity of product / service which fails to meet with the required specification but is capable of receiving amendment to meet compliance is termed the “Rework level”. The Rework level may be considered as a measures of the organizations effectiveness of meeting customer expectations first time without the requirement for correction or alteration.
Usually expressed as a percentage relating to a production “run” or period of service and based on a frequency appropriate for the business. Identification of the number of products from a production run / service period which require re work (and are subsequently passed as compliant with the original specification).
1000 gear shafts are inspected to identify any which fall outside tolerance; 2 of the shafts are identified as oversize. 2 of the shaft are re worked and subsequently passed as within specified tolerance. 2 divided by 1000 = 0.002 0.002 x 100 = 0.2% Rework level.