(h) Statements of thedefect rate (DR) for the population are stated as
"The contractor's defect rate for this work requirement is X %" (where X is
the observed defect rate minus an adjustment factor).
(i) Using random sampling, any occurrence of work is as likely to be
monitored as any other occurrence. The QAE's bias does not affect the
specific occurrences of work selected for evaluation, since all occurrences
of an item of work are assumed to have the same level of importance.
(j) Random sampling can be used to serve two purposes:
(1) To determine the performance of the contractor based on a
small number of samples of the total population,
(2) To determine the defects in the total population for the
purpose of extrapolating deductions to the contract price.
When random sampling is used to satisfy both purposes, it is referred to as
"Random Sampling for Extrapolated Deductions" or "RSED."
When nonconforming work found in the sample is not extrapolated to make
deductions to the contract price, only the first purpose noted above is
satisfied, and the method is referred to as "Random Sampling without
Extrapolated Deductions" or RSWED."
(k) RSED is the preferred method for random sampling when random
sampling is otherwise desirable. However, RSWED has particular utility when
a decision is made to carry out random sampling on an ongoing contract where
no provision has been made in the contract documents for RSED. RSED has
only slightly more rigorous requirements than RSWED, and the time
required for additional sampling is not significant. It may be argued that
the calculation of deductions using RSED is somewhat complex. However, RSED
computer programs greatly simplify calculations and invalidate the
complexity of the calculations as an excuse for not using RSED. The computer
programs are available from the EFDs.
(1) The RSED and RSWED statistical surveillance techniques have been
approved by NAVFACENGCOMHQ, and alternative methods of random sampling may
not be used without approval from NAVFACENGCOMHQ Code 022.
4-350 Validated Customer Complaints. Validated customer complaints
constitute a surveillance method based on customer awareness. Customers
familiar with the contract requirements notify the QAE of individual
occurrences of unsatisfactory performance by the contractor. Upon
notification, the QAE investigates the report and, if valid, documents the
performance problem. In summary
(a) Formal customer complaints are a means of documenting certain kinds
of service problems which might not be otherwise systematically surveyed due
to limited inspection resources.
(b) Customer complaints when validated by the QAE may be used to deduct
money from the contractor's invoice.,