• 대한인간공학회지
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• 제30권5호
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• pp.645-650
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• 2011

Objective: The aim of this study is to design a sampling inspection plan with human error which is changing according to inspection time. Background: Typical sampling inspection plans have been established typically based on an assumption of the perfect inspection without human error. However, most of all inspection tasks include human errors in the process of inspection. Therefore, a sampling inspection plan should be designed with consideration of imperfect inspection. Method: A model for single sampling inspection plans were proposed for the cases that visual inspection error rate is changing according to inspection time. Additionally, a sampling inspection plan for an optimal inspection time was proposed. In order to show an applied example of the proposed model, an experiment for visual inspection task was performed and the inspection error rates were measured according to the inspection time. Results: Inspection error rates changed according to inspection time. The inspection error rate could be reflected on the single sampling inspection plans for attribute. In particular, inspection error rate in an optimal inspection time may be used for a reasonable single sampling plan in a practical view. Conclusion: Human error rate in inspection tasks should be reflected on typical single sampling inspection plans. A sampling inspection plan with consideration of human error requires more sampling number than a typical sampling plan with perfect inspection. Application: The result of this research may help to determine more practical sampling inspection plan rather than typical one.

• 품질경영학회지
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• 제7권2호
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• pp.17-21
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• 1979

There are many kinds of the mathematical models which are developed for choosing the economic inspection plan. The aim of this paper is to classify these mathematical models, and to examine their characteristics. The mathematical models for choosing the economic inspection plan can be classified into three groups. The first of it is the break-even analysis, the second group of the model is to choose the inspection plan so as to minimize total sampling inspection cost function, and the third group of it is the model to choose the inspection plan which maximize the profit function of the sampling inspection. As a result of examining the characteristics of this classified group of the models the model to choose the inspection plan which minimize total sampling inspection cost is more economical than the other models.

• 품질경영학회지
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• 제17권1호
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• pp.48-59
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• 1989

The motor vehicle emission is expected to be constrained strongly in the future in accordance with the current policy as to prevention of air pollution. This paper establishes a sequential rectifying inspection plan which satisfies the standard motor vehicle emission for the automobile producers who are currently producting the automobiles with catalytic converts. This plan also considered the constraint of the effective motor vehicle emission by way of rectifying the certification test in the past. In order to evaluate the performance of the inspection plan, the recent certification test data have also been applied. The result of the application has proved that the rectified sequential inspection plan presented in this paper satisfies the standard motor vehicle emission and can be the optimal economic inspection plan. As a result the inspection plan given in this paper will be contributed to constrain the motor vehicle emission most effectively.

• 품질경영학회지
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• 제30권1호
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• pp.74-96
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• 2002

The objectives of this study is to suggest the rectifying sampling inspection plan considering quality cost. Limiting quality level(LQL) plans(also called LTPD plans) and outgoing quality(OQ) plans are considered. The Hald's linear cost model is discussed with and without a beta prior for the distribution of the fraction of nonconforming items in a lot. It is assumed that the sampling inspection is error free. We consider the design of reliability acceptance sampling plan (RASP) for failure rate level qualification at selected confidence level. The lifetime distribution of products is assumed to be exponential. MIL-STD-690C and K C 6032 standards provide this procedures. But these procedures have some questions to apply in the field. The cost of test and confidence level(1-$\beta$ risk) are the problem between supplier and user. So, we suggest that the optimal life test sampling inspection plans using simple linear cost model considering product cost, capability of environment chamber, environmental test cost, and etc. Especially, we consider a reliability of lots that contain some nonconforming items. In this case we assumed that a nonconforming item fail after environmental life test. Finally, we develope the algorithm of the optimal sampling inspection plan based on minimum costs for rectifying inspection and RASP. And computer application programs are developed So, it is shown how the desired sampling plan can be easily found.

• 품질경영학회지
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• 제15권2호
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• pp.55-60
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• 1987

A rectifying inspection plan which assumes a gamma - prior distribution on the lot percent defective is considered. This sampling inspection plan is developed for finite lot sizes with matching OC curves and generated from an initial plan selected from KS A 3102 single sampling by attributes. Comparisons are made with each plan by three examples.

• 품질경영학회지
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• 제8권2호
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• pp.15-22
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• 1980

This paper deals with the problem of determining a minimum cost sampling inspection plan for a single destructive testing by attribute. The cost for inspection lot is constructed by following three cost factors: (1) cost of inspection, (2) cost of accepted defective, (3) cost of rejected lot Using Hald's Bayesian approach in a single non-destructive testing, procedure's for finding the minimum cost single destructive sampling inspection plan by attribute are given. Assuming the uniform distribution as a prior-distribution and using numerical analysis by computer, a minimum cost single destructive sampling inspection plan by attribute for several lot sizes, unit cost, destructive testing cost, and salvage cost is given.

• 응용통계연구
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• 제10권2호
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• pp.375-384
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• 1997

본 연구에서는 가장 수월한 검사계획의 성격을 띄는 Choi(1993)의 검사계획과 까다로운 검사계획의 성격을 띄는 Choi(1995)의 검사계획의 중간 단계인 보통검사계획의 성격을 띄는 사슬모양의 다단계 스킵-로트 샘플링 검사계획을 설계하였다. 이 검사계획에서는 각 단계의 검사에서 정해진 갯수의 로트가 연속적으로 합격될 때에는 다음 단계의 검사로, 로트가 불합격될 때에는 그 전전 단계의 검사로 전환하도록 되어 있다. 마코프 연쇄를 이용하여 사슬모양의 3단계 스킵-로트 샘플림 검사계획의 검사특성곡선, 평균검사갯수와 평균출검품질을 구하여 Choi(1993) 및 Choi(1995)의 검사계획들과 그 성질을 비교하였다.

• Industrial Engineering and Management Systems
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• 제15권1호
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• pp.41-48
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• 2016

In this manuscript, a modified single sampling plan is proposed for the inspection of products in which the nonconforming items can be classified in to two categories namely critical and non-critical; and explained with the help of industrial example. The operating procedure of this plan is also proposed and the performance measures such as the probability of acceptance, average sample number, average total inspection and average out going quality are also derived. The optimal parameters are determined which will have minimum sample size. The efficiency of the proposed plan is also discussed over the conventional single sampling plan. The extensive tables for selecting a modified single sampling plan based on AQL and LQL are provided for both Binomial and Poisson distributions and explained with the help of industrial data.

• 한국경영과학회지
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• 제18권1호
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• pp.97-117
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• 1993

This paper considers inspection station location problem for a flexible assembly line that consists of multiple stages. By considering the trade-off between locating an station at an "early" stage and at a "late" stage, we have developed some dominance relations on a graph. Based on the dominance relations, we then present an algorithm that finds an optimal inspection plan and a heuristic approach that finds a near-optimal inspection plan. The effectiveness of these two algorithms is demonstrated by two numerical examples. numerical examples.

• 품질경영학회지
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• 제21권1호
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• pp.65-77
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• 1993

Often in a production process, the quality of items is serially dependent. We assume that the quality of items is an attribute which can be classified as good or bad with a Markovian dependence structure. In order to determine sampling inspection plan characteristics such as total inspection cost and average outgoing quality, we design an economic model and illustrate an efficient procedure for design of best inspection plan using graphs based on numerical calculations.