• Title/Summary/Keyword: nonconforming

Search Result 128, Processing Time 0.031 seconds

Analysis of the Manufacturing Process using Multiple Comparison Procedure (다중비교 절차를 이용한 제조공정의 분석)

  • 최봉욱;김광섭
    • Journal of Korean Society of Industrial and Systems Engineering
    • /
    • v.20 no.44
    • /
    • pp.333-341
    • /
    • 1997
  • The purpose of this paper is to compare the manufacturing process with random covariate using multiple comparison procedure. The methodology that compares each manufacturing process by inspecting the number of nonconforming items out of k-treatment, has serveral limitations and problems according to the method and contect of the analysis. The proper way of analysis, therefore, could be obtained by the multiple comparison procedure of simultaneous confidence region of variance components. Effections that affect a manufactuing process may be predictive of responce to treatments are called covariates. In the study of comparing several treatments, prsense of covariate may bias the estimates of treatment effects.

  • PDF

A Process Improvement of the SMPS Assembly Line Using Motion Study and Line Balancing Techniques (동작 연구 및 라인 발란싱을 활용한 SMPS 조립라인의 공정개선 사례)

  • Lee, Sang-Young;Hong, Sung-Hoon;Kim, Jin-Hwan
    • IE interfaces
    • /
    • v.11 no.3
    • /
    • pp.155-166
    • /
    • 1998
  • The productivity and quality are most challenging problems facing all companies. This paper presents a process improvement of the SMPS(switching mode power supply) assembly line through elimination of unnecessary operations, a proper factory layout, motion study, and line balancing techniques. The proposed assembly line increases the productivity by 23.9%, and decrease the proportion of nonconforming items by 48.9%.

  • PDF

MULTIGRID CONVERGENCE THEORY FOR FINITE ELEMENT/FINITE VOLUME METHOD FOR ELLIPTIC PROBLEMS:A SURVEY

  • Kwak, Do-Y.
    • Journal of the Korean Society for Industrial and Applied Mathematics
    • /
    • v.12 no.2
    • /
    • pp.69-79
    • /
    • 2008
  • Multigrid methods finite element/finite volume methods and their convergence properties are reviewed in a general setting. Some early theoretical results in simple finite element methods in variational setting method are given and extension to nonnested-noninherited forms are presented. Finally, the parallel theory for nonconforming element[13] and for cell centered finite difference methods [15, 23] are discussed.

  • PDF

Demerit-EWMA Control Charts

  • Cho, Gyo-Young;Jeon, Young-Mok
    • 한국데이터정보과학회:학술대회논문집
    • /
    • 2004.04a
    • /
    • pp.7-14
    • /
    • 2004
  • In this paper, we present an effective method for process control using the Demerit-EWMA control chart in the process where nonconforming units or nonconformities are occurred by various types. We compare performance of Demerit control chart, Demerit-CUSUM control chart and Demerit-EWMA control chart based on the average run length.

  • PDF

The Design of Control Chart Based on a Short-run Production Process (단속공정 품질관리도 설계)

  • 김종걸;정연승
    • Proceedings of the Safety Management and Science Conference
    • /
    • 2000.11a
    • /
    • pp.217-234
    • /
    • 2000
  • Approximately normalized control charts, called Q charts, have been given Quesenberry(1991) for charting in process of short-run, job-shop, etc. We consider a Q chart with inspection error for job-shop floor under geometric distribution, which can be used for processes when a fraction nonconforming is very small. Our results would be applied for designing other control charts with inspection error.

  • PDF

Measuring Process Capability with Beta Distributions (베타분포의 공정능력 평가)

  • 김진수;김홍준
    • Journal of Korean Society of Industrial and Systems Engineering
    • /
    • v.22 no.50
    • /
    • pp.281-291
    • /
    • 1999
  • This paper is a brief review of the different procedures that are available for fitting theoretical distributions to data. The use of each technique is illustrated by reference to a distribution system which including the Pearson, Johnson and Burr functions. These functions can be used to calculate percent out of specification. The main objectives of this study are to propose a new methods for estimating a measure of process capability for Beta distributed variable data by using the percentage nonconforming. The comprehensive information for the process can be used to evaluate more accurately process capability.

  • PDF

A Study of Demerit-EWMA Control Charts

  • Cho, Gyo-Young;Jeon, Young-Mok
    • Journal of the Korean Data and Information Science Society
    • /
    • v.15 no.2
    • /
    • pp.431-439
    • /
    • 2004
  • In this paper, we present an effective method for process control using the Demerit-EWMA control chart in the process where nonconforming units or nonconformities are occurred by various types. We compare performance of Demerit control chart, Demerit-CUSUM control chart and Demerit-EWMA control chart based on the average run length(ARL).

  • PDF

Rectifying Inspection of Linear Cost Model with a Constraint and a $\alpha$-Optimal Acceptance Sampling (제약조건과 사전확률이 고려된 선형비용모형의 수정검사정책)

  • 이도경;이근희
    • Journal of Korean Society of Industrial and Systems Engineering
    • /
    • v.14 no.24
    • /
    • pp.1-5
    • /
    • 1991
  • Various linear cost models have been proposed that can be used to determine a sampling plan by attributes. This paper is concerned with this sampling cost model when the probability that the number of nonconforming item is smaller than the break-even quality level is known. In addition to this situation, a constraint by AOQL is considered. Under these conditions, optimal sampling plan which minimize the average cost per lot is suggested.

  • PDF

A Comparative Study on the Evaluation of Process Capability for Non-Normal Distributions (비정규분포에 대한 공정능력 평가에 관한 비교 연구)

  • 이상용;채규용
    • Journal of Korea Society of Industrial Information Systems
    • /
    • v.5 no.3
    • /
    • pp.77-86
    • /
    • 2000
  • The main objectives of this dissertation is to propose a forth generation index C for the case where the target value T is not equal to the midpoint of the specification limits (i.e. asymmetric tolerances), and show that this index is more sensitive compared to the standard PCI's in detacting small shifts of the process mean from the target value. In conclusion, in this dissertation , a new methods for estimating a measure of process capability for non-normally distributed variable data is proposed using the percentage nonconforming.

  • PDF

Measure of Evaluation for Non-Normal Process Capability (비정규 공정능력 평가의 측도)

  • 김홍준;김진수;전창희
    • Journal of the Korea Safety Management & Science
    • /
    • v.2 no.2
    • /
    • pp.41-55
    • /
    • 2000
  • The main objective of this paper is to propose a measure of evaluation for non-normal process capability. If a process is not normally distributed, but normal-based techniques are used, serious errors can result. Our approach to solve this problem is that the Pearson system, the Johnson system, and the Burr system are selected for estimating a measure of process capability using the percentage nonconforming. In this paper, we found that the Pearson system and the Johnson system were a conparatively reasonable methods to calculate out of specification by example.

  • PDF