Managing Quality
Cost Effective Testing and Inspection (CETI) is a management tool for providing improved quality assurance while significantly reducing quality costs and answering management's oft-asked question, "Just how much inspection should we have?"
CETI accomplishes this by integrating the several process factors and key inspection features.
Analyzing Quality
CETI is based on the algorithm Acheson J. Duncan first published in an article in 1956 and later in his book on Quality Control and Industrial Statistics . Analyzing the input variables, it defines the lowest combined cost for a given process or operation. The results identify the optimal sample size, inspection frequency, and control limits, together with estimates of producer and consumer risks.
Although primarily applied in the manufacturing environment, CETI results thus far suggest that this management tool can reduce total quality costs by five to ten percent. CETI provide you the capability to analyze your inspection process and balance sample size, testing/inspection frequency, cost and error rate (sigma level) to your quality goals.
Real World Sample
Test: A local company conducts 10 quality tests every eight hours at an average hourly cost of $15.81.
The CETI process and software results:
Result: If the optimal choice is implemented the company conducts 3 tests every 3.38 hours @ $12.34 per hour resulting in a $3.47 (21.9%) savings.
Getting Started
Before beginning any CETI study, you will need to collect data on the nine parameters used in the program. This data includes:
> cost data on the inspection and testing process (4 parameters)
> cost of remaining out-of-control for an hour
> data calculated from the process control sheets (2 parameters)
> time data associated with the testing and inspection process, and implementing corrections when the process is found to be out-of-control