• Title/Summary/Keyword: Process

Search Result 114,562, Processing Time 0.198 seconds

Optimization of Process Capability Index for Economic Coalify Assurance Level (경제적인 품질보증수준확보를 위한 공정능력지수의 최적화에 관한 연구)

  • 송서일
    • Journal of the Society of Korea Industrial and Systems Engineering
    • /
    • v.11 no.18
    • /
    • pp.71-80
    • /
    • 1988
  • Process capability implies the qualitative capability of a process, and it is necessary to specify the process capability by quantification and to evaluate the level with the specified standardizaion. But the process capability index is currently used to evaluate the performance of quality control activity. without considering the characteristics of process structure or the economy of management. Here the researcher would like to redefine process capability and emphasize its index may be used as the measure of managerial assessment and the objective of process quality control in full consideration of the economic aspects of process characteristics. Too little or too much process capability causes a loss of or excess. The proper economic level of process capability varies to each process. The procedure of taking the optimum process capability index is derived from the expected profit function, whereas each method is studied in cases of normal process with one-sided specification and two-sided specification. In addition, the process capability index is presented as a method of quality assurance. And an example is exhibited on wrapping process of 'A' company. The results of this study are summarized at follows. First, though the norminalization of the process capability index is possible by the existing methods, the optimum process capability index can vary to the situation of each process. So, the optimum process capability index which is suggested in this dissertation should be used as the standard to assess process capability. Second, the process capability index can take its effect not just in indicating quality control or managerial records but also in the management of high qualify assurance.

  • PDF

Comparison and Application of Process Capability indices (공정능력지수에 대한 비교와 적용)

  • Chung, Young-Bae;Kim, Yon-Soo
    • Journal of the Society of Korea Industrial and Systems Engineering
    • /
    • v.30 no.4
    • /
    • pp.182-189
    • /
    • 2007
  • Process Capability indices(PCIs) have been widely used in manufacturing industries to provide a quantitative measure of process performance. PCIs have been developed to represent process capability more exactly. The traditional process capability indices Cp, Cpk, Cpm, $Cpm^+$ have been used to characterize process performance on the basis of univariate quality characteristics. Cp, Cpk consider the process variation, Cpm considers both the process variation and the process deviation from target and $Cpm^+$ considers economic loss for the process deviation from target In the previous studies, only one designated location on each part is measured. System process capability index even though in single process, multiple measurement locations on each part are required to calculate the reliable process capability. In manufacturing industry, there is growing interest in quantitative measures of process variation under multivariate quality characteristics. The multivariate process capability index incorporates both the process variation and the process deviation from target or considers expected loss caused by the process deviation from target. In this paper, we compare various process capability indices and propose the application method of PCIs.

A Study on the Construction and Improvement of Software Process Infrastructure for Software Firms In Korea (국내 소프트웨어 사업자의 프로세스 기반구조 구축 및 개선 방안 연구)

  • Ahn, Yeon-Shick;Moon, Song-Chul;Kim, Dong-Soo
    • Asia pacific journal of information systems
    • /
    • v.14 no.4
    • /
    • pp.23-47
    • /
    • 2004
  • This study was tried for the improvement of software process ability of the software firms, and analyzed empirically the impact that a software process infrastructure level influences on the software process level and process performance. The questionnaire were developed and data were collected from the process improvement correspondences or project quality managers of the 78 software firms. The result was shown that management-organization infrastructure was composed of software process improvement organization's role and activity, process standard and education, management system and supporting, management guides and procedures. And organization's standard development procedure or criteria, process asset, process support tools were included in technical infrastructure. This study provides that some components of software process infrastructure had an significant influence on the process level, process infrastructure management level, and software process performance.

Applications of Product Process Analysis For Improving the Construction Process of Structural Steel

  • Lee Seung-Hyun
    • Korean Journal of Construction Engineering and Management
    • /
    • v.5 no.5
    • /
    • pp.101-108
    • /
    • 2004
  • A construction process consists of value adding activities and non-value adding activities, necessary or unnecessary. If construction personnel can eliminate inefficient and/or unnecessary activities within the process, they may have a great opportunity to improve their construction process. The Product Process Analysis (PPA) technique, which was developed in the manufacturing industry, can be applied for identifying wastes in the construction process and ultimately improving the process itself. It provides useful tools, such as a process chart worksheet and flow diagram, for mapping the flow of construction activities with predetermined standardized symbols. These tools make people understand the flow of activities more easily, identify value adding/non-value adding activities within the process, and areas where the process can be improved. The example applications of PPA are demonstrated in the paper through the case studies implemented on the construction process of structural steel. The results of case studies indicate that PPA technique was effective at identifying and removing wastes in the steel construction process. It is also found that PPA technique is more effective for improving highly repetitive construction processes.

Dynamic Process Capability Indices

  • Sun, Jing
    • International Journal of Quality Innovation
    • /
    • v.3 no.2
    • /
    • pp.74-83
    • /
    • 2002
  • Process capability indices as an important kind of indices are intended to provide single-number assessments of the inherent process capability to meet specification limits on quality characteristic(5) of interest. In this paper the condition for the application of process capability indices is analyzed. On the basis of process capability indices, dynamic process capability indices as a new kind of indices to show the current process capability are discussed and the condition for the application of dynamic process capability indices is exhibited. Comparison between process capability index and dynamic process capability index and comparison between $D_p$ and $D_pk$ are made and the conclusions provide the approach for process control. According to the requirement of process capability indices provided by customer, quality control based on process capability indices dynamic process capability indices is discussed.

An Interpretation of Process Capability Index and Process Performance Index

  • Nam, Ho-Soo
    • Journal of the Korean Data and Information Science Society
    • /
    • v.13 no.2
    • /
    • pp.285-294
    • /
    • 2002
  • The control chart is widely used tool for monitoring of the process. This paper deals with an interpretation of the process capability index(PCI) and process performance index(PPI) when the control chart is used for monitoring of the process. The main difference between the PCI and PPI is how we did estimate the process deviation. The PCI uses the within process variation and the PPI uses the total process variation, which is conceptually defined as sum of between process variation and within process variation. Easy interpretations of the PCI and PPI for field engineers are described. And some new approaches to interpretation of the process capability and performance index may be useful in early stabilization of new process.

  • PDF

Optimal Process Design of Super Junction MOSFET (Super Juction MOSFET의 공정 설계 최적화에 관한 연구)

  • Kang, Ey Goo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.27 no.8
    • /
    • pp.501-504
    • /
    • 2014
  • This paper was developed and described core-process to implement low on resistance which was the most important characteristics of SJ (super junction) MOSFET. Firstly, using process-simulation, SJ MOSFET optimal structure was set and developed its process flow chart by repeated simulation. Following process flow, gate level process was performed. And source and drain level process was similar to genral planar MOSFET, so the process was the same as the general planar MOSFET. And then to develop deep trench process which was main process of the whole process, after finishing photo mask process, we developed deep trench process. We expected that developed process was necessary to develop SJ MOSFET for automobile semiconductor.

An Improved Process Incapability Index for the Evaluation of Process Capability (공정능력의 평가를 위한 개선된 비공정능력지수)

  • Shin, Kyung-seok;Kim, Seong-Jip;Kang, Chang-wook
    • Journal of the Korean Society for Quality Management
    • /
    • v.24 no.4
    • /
    • pp.90-102
    • /
    • 1996
  • Process incapability index which is intended to evaluate the process capability by measuring process incapability provides more detailed information by dividing information about the process mean and variance. But when the target value is not consistent with the center of specification, it is very difficult to evaluate the process capability accurately. Thus it is necessary to improve the existing process incapability index. The improved process incapability index can identify the variation of the process faster than other process capability indices when applied firstly, to the precision process which can be affected sensitively by the change of the process, secondly, to the ordinary process where cost difference from the change of process is noticeable. By using subindices such as inaccuracy index and imprecision index, it is easier for quality manager to find where the cause of the variation of process is, and to take necessary action in advance.

  • PDF

A Study on the Optimization of Deburring Process for the Micro Channel using EP-MAP Hybrid Process (전해-자기 복합 가공을 이용한 마이크로 채널 디버링공정 최적화)

  • Lee, Sung-Ho;Kwak, Jae-Seob
    • Journal of the Korean Society of Manufacturing Technology Engineers
    • /
    • v.22 no.2
    • /
    • pp.298-303
    • /
    • 2013
  • Magnetic abrasive polishing is one of the most promising finishing methods applicable to complex surfaces. Nevertheless this process has a low efficiency when applied to very hardened materials. For this reason, EP-MAP hybrid process was developed. EP-MAP process is expected to machine complex and hardened materials. In this research, deburring process using EP-MAP hybrid process was proposed. EP-MAP deburring process is applied to micro channel, thereby it can obtain both deburring process and polishing process. EP-MAP deburring process on the micro channel was performed. Through design of experiment method, error of height in this process according to process parameter is analyzed. When the level 1 parameter A(magnetic flux density) and level 2 parameter B(electric potential), C(working gap) and level 3 parameter D(feed rate) are applied in the deburring process using EP-MAP hybrid process, it provides optimum result of EP-MAP hybrid deburring process.

Decision-Making of Casting Process using Expert System (전문가 시스템을 이용한 주조법 결정)

  • Kim, Jong-Do;Yoon, Moon-Chul
    • Journal of the Korean Society of Manufacturing Process Engineers
    • /
    • v.13 no.6
    • /
    • pp.54-60
    • /
    • 2014
  • In industry, several casting process are widely used to manufacture complex and accurate blank part of hard materials such as aluminum, casting steels, bronze and magnesium alloys which are difficult to manufacture in a blank shape. Even if the casting process does not high accuracy superior surface characteristics other machining process, the casting process is widely used in manufacturing blank part. Furthermore, it is difficult to select appropriate casting process a part among several casting process. for effective selection different process, a careful decision given casting application is necessary. An appropriate casting for a given material and shape condition must be selected for novice engineers in industry. In this paper, an expert system based on an analytic network process(ANP) is suggested for best selection of casting considering a prior interdependency effect among various factors such as material, geometry, process capability, economy and equipment.