• Title, Summary, Keyword: statistical process control

Search Result 529, Processing Time 0.034 seconds

Overview of Operations Strategy for Service Layout and Statistical Process Control (서비스 배치 및 SPC 운영 전략)

  • Choi, Sung-Woon
    • Journal of the Korea Safety Management & Science
    • /
    • v.8 no.6
    • /
    • pp.109-118
    • /
    • 2006
  • This paper proposes service layout strategy considering service characteristics by the use of benchmarking production system such as layout by P-Q chart, improvement tool, automated system, Toyota production system and lean production system. This paper represents operation methodology of statistical process control using control chart for service performance outcomes.

Development of Integrated Variable Sampling Interval Engineering Process Control & Statistical Process Control System (가변 샘플링간격 EPC/SPC 결합시스템의 개발)

  • Lee, Seong-Jae;Seo, Sun-Geun
    • Proceedings of the Korean Operations and Management Science Society Conference
    • /
    • /
    • pp.723-729
    • /
    • 2005
  • Traditional statistical process control(SPC) applied to discrete part industry in the form of control charts can look for and eliminate assignable causes by process monitoring. On the other hand, engineering process control(EPC) applied to the process industry in the form of feedback control can maintain the process output on the target by continual adjustment of input variable. This study presents controlling and monitoring rules adopted variable sampling interval(VSI) to change sampling intervals in a predetermined fashion on the predicted process levels for integrated EPC and SPC systems. Twelve rules classified by EPC schemes(MMSE, constrained PI, bounded or deadband adjustment policy) and type of sampling interval combined with EWMA chart of SPC are proposed under IMA(1,1) disturbance model and zero-order (responsive) dynamic system. The properties of twelve control rules under three patterns of process change(sudden shift, drift and random shift) are evaluated and discussed through simulation and control rules for integrated VSI EPC and SPC systems are recommended.

  • PDF

Literature Review on the Statistical Quality Control in Journal of the KSQM for 50 Years (품질경영학회지 50주년 특별호: 통계적품질관리 분야 연구 리뷰)

  • Kwon, Hyuck Moo;Hong, Sung Hoon;Lee, Min Koo;Lim, Sung Uk
    • Journal of the Korean Society for Quality Management
    • /
    • v.44 no.1
    • /
    • pp.1-16
    • /
    • 2016
  • Purpose: This paper reviews the papers on statistical quality control issues which are published in Journal of the Korean Society for Quality Management (KSQM) since 1965. The literature review is purposed to survey a variety of statistical quality control issues. Methods: By grouping all of statistical quality control issues into 3 categories:; quality inspections, control charts, and process capability analysis. Results: Grouping all of papers on statistical quality control published in journal of the KSQM for 50 years into 3 categories, we provide a chronological roadmap for individual categories, and summarize the contents and contributions of surveyed papers. Conclusion: The review paper is expected to provide future direction to improve statistical quality control theories and applications in manufacturing and service industries.

The CV Control Chart

  • Kang, Chang-W;Lee, Man-S;Hawkins, Douglas M.
    • Proceedings of the Korean Society for Quality Management Conference
    • /
    • /
    • pp.211-216
    • /
    • 2006
  • Monitoring variability is a vital part of modem statistical process control. The conventional Shewhart Rand S charts address the setting where the in-control process readings have a constant variance. In some settings, however, it is the coefficient of variation, rather than the variance, that should be constant. This paper develops a chart, equivalent to the S chart, for monitoring the coefficient of variation using rational groups of observations.

  • PDF

A Generalization of the Discrete Feedback Adjustment by Rational Subgrouping

  • Park, Changsoon;Moonsup Song;Lee, Jaeheon
    • Journal of the Korean Statistical Society
    • /
    • v.27 no.2
    • /
    • pp.237-249
    • /
    • 1998
  • Process adjustment has been widely used in production processes in order to set the output characteristic as close as to the target. Box and Kramer(1992) developed a feedback adjustment control procedure for process adjustment. We generalize their procedure by using a rational subgrouping of sequential observations. In this paper the feedback control rule of the rational subgrouping is proposed and the overall expected cost is evaluated. Also properties of the proposed control scheme are illustrated and compared to Box and Kramer's in the context of the expected cost.

  • PDF

Determination of Quality Cost Policy under Multiple Assignable Causes (다중이상원인하의 경제적 품질비용 정책결정)

  • 김계완;김용필;박지연;윤덕균
    • Journal of the Society of Korea Industrial and Systems Engineering
    • /
    • v.26 no.1
    • /
    • pp.7-16
    • /
    • 2003
  • At present, company has to produce a product that consumer like with a competitive price, a good quality, and a fitting time to supply. Process control and quality control are very important to supply with a product uniformly and inexpensively. Process control is given much weight in the quality control in manufacturing system. Statistical process controls(SPC) that are used in process generally have major impact on manufacturing, product design activities, and process development potentially. Control charts in statistical process control method can be interpreted the data from quality characteristics in production process and discriminated between chance variation and assignable variation in process. In addition, control chart can be used to monitor the process output and detect when changes in the inputs are required to bring the process back to an in-control state. The models that relate the influential inputs to process outputs help determine the nature and magnitude of the adjustments required. In this paper, the characteristic of product quality is monitored by control chart during the machining process and construction of quality control cycle is considered to divide into two types in this case that different assignable causes lead to shifts having different magnitudes. Then we are intended to find a process shift magnitude which has economical quality cost policy and are considered to quality cost functions to find a process shift magnitude. Those costs are categorized into the well-known categories of prevention, appraisal, and internal failure and external failure. This paper ends with numerical examples that demonstrate the usefulness of the model.

Statistical Process Control of Stochastic Network for the evaluation of six sigma Level (확률적 네트워크의 통계적 공정관리와 6$\sigma$)

  • 박기주
    • Journal of the Korea Industrial Information Systems Research
    • /
    • v.8 no.1
    • /
    • pp.1-8
    • /
    • 2003
  • There are many statistical evaluation methods, A more technical Perspective is needed in estimating the effect of the Manufacturing Process for improving the Productivity, Process network analysis is a technique which has the potentiality for a wire use to improve the manufacturing process which other techniques can't be used to analyze effectively. The concept of six sigma plan was developed and pursued by Motorola to improve the process control. The goals of six sigma plan are established on the foundation of customer satisfaction such as Quality, Cost Delivery and Service This paper presents how to improve the manufacturing process by statistical process control for the evaluation of six sigma level.

  • PDF

Economic Performance of an EWMA Chart for Monitoring MMSE-Controlled Processes

  • Lee, Jae-Heon;Yang, Wan-Youn
    • Journal of the Korean Data and Information Science Society
    • /
    • v.15 no.2
    • /
    • pp.285-295
    • /
    • 2004
  • Statistical process control(SPC) and engineering process control(EPC) are two complementary strategies for quality improvement. An integrated process control(IPC) can use EPC to reduce the effect of predictable quality variations and SPC to monitor the process for detection of special causes. In this paper we assume an IMA(1,1) model as a disturbance process and an occurrence of a level shift in the process, and we consider the economic performance for applying an EWMA chart to monitor MMSE-controlled processes. The numerical results suggest that the IPC scheme in an IMA(1,1) disturbance model does not give additional advantages in the economic aspect.

  • PDF

Comparison and Evaluation of Performance for Standard Control Limits and Bootstrap Percentile Control Limits in $\bar{x}$ Control Chart ($\bar{x}$ 관리도의 표준관리한계와 부트스트랩 백분률 관리한계의 수행도 비교평가)

  • 송서일;이만웅
    • Journal of the Society of Korea Industrial and Systems Engineering
    • /
    • v.22 no.52
    • /
    • pp.347-354
    • /
    • 1999
  • Statistical Process Control(SPC) which uses control charts is widely used to inspect and improve manufacturing process as a effective method. A parametric method is the most common in statistical process control. Shewhart chart was made under the assumption that measurements are independent and normal distribution. In practice, this assumption is often excluded, for example, in case of (equation omitted) chart, when the subgroup sample is small or correlation, it happens that measured data have bias or rejection of the normality test. A bootstrap method can be used in such a situation, which is calculated by resampling procedure without pre-distribution assumption. In this study, applying bootstrap percentile method to (equation omitted) chart, it is compared and evaluated standard process control limit with bootstrap percentile control limit. Also, under the normal and non-normal distributions, where parameter is 0.5, using computer simulation, it is compared standard parametric with bootstrap method which is used to decide process control limits in process quality.

  • PDF