Economic Design of A Dynamic CCC – r Chart for High-Yield Processes
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Kazuki Kudo
Abstract
Recently, Ohta et al. [Quality and Reliability Engineering International 17: 439-446, 2001] have studied the economic design of CCC(Cumulative Count of Conforming)-r charts for high-yield processes assuming a fixed hazard rate. Generally, however, the hazard rate is varying over time. With the ageing of a process, the hazard rate gets first gradually smaller, while during the last stage of the wear-out process, the hazard rate increases. For such processes, the Weibull distribution is used to model the circumstances. In this paper, we discuss an economic design of a dynamic CCC – r chart with time-varying parameters. Concretely, we propose a process control model for a Weibull distributed-shock model and determine the initial values and dynamic decision rules for the time-varying parameters of the CCC–r chart, that is, the required number of nonconforming observations r, the sampling interval h, and the lower control limit LCL maximizing the expected profit per unit time derived from the process. Finally, we compare the profits obtained applying a dynamic CCC – r chart with those obtained with a traditional static CCC – r chart.
© Heldermann Verlag
Articles in the same Issue
- Economic Design of A Dynamic CCC – r Chart for High-Yield Processes
- A Note on Average Run Lengths of Moving Average Control Charts
- A Group Runs Control Chart for Detecting Shifts in the Process Mean
- A Capability Index Calibrated to the Nonconformance Probability
- Stochastic Methods for Production Processes
- Parametric Bivariate Regression Analysis Based on Censored Samples: A Weibull Model
- A Note on Savings in Experimental Time Under Type II Censoring
- Expected Time for Attainment Threshold Level A Shock Model Approach
- Maintenance Models for a Repairable System
- Minimum Average Fraction Inspected for Combined Continuous Lot by Lot Acceptance Sampling Plan
- Minimum Risk Acceptance Sampling Plans: A Review
- Improving Resistivity of Resin
Articles in the same Issue
- Economic Design of A Dynamic CCC – r Chart for High-Yield Processes
- A Note on Average Run Lengths of Moving Average Control Charts
- A Group Runs Control Chart for Detecting Shifts in the Process Mean
- A Capability Index Calibrated to the Nonconformance Probability
- Stochastic Methods for Production Processes
- Parametric Bivariate Regression Analysis Based on Censored Samples: A Weibull Model
- A Note on Savings in Experimental Time Under Type II Censoring
- Expected Time for Attainment Threshold Level A Shock Model Approach
- Maintenance Models for a Repairable System
- Minimum Average Fraction Inspected for Combined Continuous Lot by Lot Acceptance Sampling Plan
- Minimum Risk Acceptance Sampling Plans: A Review
- Improving Resistivity of Resin
