This paper reports the findings of research by the Roads and Traffic Authority of NSW (RTA) into current acceptance sampling and process control procedures to deliver base course thickness. Estimation of the effect of data correlation on decisions about process control enabled the research to develop statistically based acceptance sampling plans for concrete base course thickness. The paper also explains the risks associated with acceptance sampling and the statistical theory relating to risk sharing between producers and consumers. The paper shows that acceptance should be based on process measurements instead of relying on product measurements as at present. An outline describing implementation of the acceptance sampling plans shows the incentives that process measurement gives contractors to adopt statistical process control and the benefits of this to the RTA. The research also determined the measurement accuracy required to track process improvement. (A)
Samenvatting