• Title, Summary, Keyword: Process

Search Result 113,910, Processing Time 0.157 seconds

Improvement Plan of Daily Work Accomplishment Index based Process Management based on Lean Construction Principles

  • Yoo, Dong Uk;Hong, Eun Hwa;Choi, Byung Sun;Chae, Myung Jin;Chun, Jae Youl
    • Architectural research
    • /
    • v.20 no.4
    • /
    • pp.147-152
    • /
    • 2018
  • As construction projects become larger, process plans become more complex, and inadequate process management leads to waste of time and resources. Effective process management requires process management techniques that can identify problems inherent in the process, continuously improve, and reflect interdependent process characteristics. In the field, the day's details by work type and work status are to be entered in the work daily report. However, even when important information is written, it is not directly linked to the overall process management. This study aims to propose specific process management and decision-making plan based on actual worker by visualizing and quantifying the information described in the existing work daily report. It is expected efficient process management to increase reliability and productivity through process management, which can increase the utilization of work daily reports and facilitates organic communication among participants.

Economic Selection of Optimum Process Mean for a Mixture Production Process (혼합물 생산공정의 최적 공정평균의 경제적 선정)

  • Lee, Min-Koo
    • Journal of the Korean Society for Quality Management
    • /
    • v.33 no.4
    • /
    • pp.111-116
    • /
    • 2005
  • This paper considers the problem of optimally choosing the sub-process means of a mixture production process where two important ingredients are mixed. The quantity of each ingredient is controlled through each corresponding sub-process. The values of the sub-process mean directly affect the defective rate, production, scrap and reprocessing costs for the mixture production process. After inspecting every incoming item, each conforming item is sold in a regular market for a fixed price and any nonconforming item is scraped. A model is constructed on the basis of the selling price, production, inspection, and scrap and reprocessing costs. The goal is to determine the optimum sub-process mean values based on maximizing expected profit function relating selling price and cost components. A method of finding the optimum sub-process means is presented when the quantities of the two ingredients are assumed to be normally distributed with known variances. A numerical example is given and numerical studies are performed.

Problems of Special Causes in Feedback Adjustment

  • Lee, Jae-June;Cho, Sin-Sup
    • Journal of the Korean Society for Quality Management
    • /
    • v.32 no.2
    • /
    • pp.201-211
    • /
    • 2004
  • Process adjustment is a complimentary tool to process monitoring in process control. Process adjustment directs on maintaining a process output close to a target value by manipulating another controllable variable, by which significant process improvement can be achieved. Therefore, this approach can be applied to the 'Improve' stage of Six Sigma strategy. Though the optimal control rule minimizes process variability in general, it may not properly function when special causes occur in underlying process, resulting in off-target bias and increased variability in the adjusted output process, possibly for long periods. In this paper, we consider a responsive feedback control system and the minimum mean square error control rule. The bias in the adjusted output process is investigated in a general framework, especially focussing on stationary underlying process and the special cause of level shift type. Illustrative examples are employed to illustrate the issues discussed.

Problems of Special Causes in Feedback Adjustment

  • Lee Jae June;Cho Sinsup;Lee Jong Seon;Ahn Mihye
    • Proceedings of the Korean Society for Quality Management Conference
    • /
    • /
    • pp.425-429
    • /
    • 2004
  • Process adjustment Is a complimentary tool to process monitoring in process control. Process adjustment directs on maintaining a process output close to a target value by manipulating another controllable variable, by which significant process improvement can be achieved. Therefore, this approach can be applied to the 'Improve' stage of Six Sigma strategy. Though the optimal control rule minimizes process variability in general, it may not properly function when special causes occur in underlying process, resulting in off-target bias and increased variability in the adjusted output process, possibly for long periods. In this paper, we consider a responsive feedback control system and the minimum mean square error control rule. The bias in the adjusted output process is investigated in a general framework, especially focussing on stationary underlying process and the special cause of level shift type. Illustrative examples are employed to illustrate the issues discussed.

  • PDF

Optimization of Glass Micro Molding Process for Glass Microlens Arrays (유리 마이크로 렌즈 어레이 성형을 위한 유리 마이크로 성형 공정 최적화)

  • Bae, Hyung-Dae;Choi, Min-Seok;Kang, Shin-Ill
    • Transactions of the Society of Information Storage Systems
    • /
    • v.2 no.4
    • /
    • pp.236-239
    • /
    • 2006
  • Glass micro molding process is the most suitable process for fabricating high precision glass microlens amy at low cost. A new glass micro molding process was proposed. Tungsten carbide mold was fabricated by imprinting and sintering process to overcome the difficulties of the conventional process. In the glass micro molding process, process conditions such as processing temperature and compression force were changed. Geometrical properties of the replicated glass microlens array were measured and compared at variety process conditions. The condition of glass micro molding process was optimized. The experimental result showed that developed process was effective to produce a glass microlens array.

  • PDF

A Life-Process Analysis of Broaching Tool (브로칭 공구의 수명 분석)

  • Lee, Sang-Cheon;Kang, Shin-Ick;Hong, Jung-Wan
    • IE interfaces
    • /
    • v.15 no.1
    • /
    • pp.64-72
    • /
    • 2002
  • Broaching machine is widely used for machining inner shaped slots in the work-pieces, and provides vertical motion (usually hydraulically powered) between tool and work-piece. In this study, we modelled the tool life process and investigated economic tool life of broaching machine. Tool life process is divided into wear-process and succeeding failure process. Wear process is defined as machining wear and failure process as 'chipping' occurred by random shock. We modelled wear process as linear regression function for products amounts and assumed failure process as Poisson process. Economic tool life is defined as the number of lots which minimizes average tool related cost per lot and analyzed by using age replacement policy technique. As tool-related cost factors, we consider tool replacement cost, tool maintenance cost and quality costs of products. The results of this study can be applied to analyze life process of general machining tools.

A Study on the Process Sequence Design of a Short-Neck Flange (숏넥 플랜지의 공정설계에 관한 연구)

  • 장용석;최진화;고병두;이호용;황병복
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.17 no.6
    • /
    • pp.127-134
    • /
    • 2000
  • The current three-stage cold farming process to produce a flange is investigated for the purpose of improvement of manufacturing process. The main goal of this study is to obtain an appropriate process sequence, which can produce the required part with less manufacturing cost. The current process sequence is simulated using finite element method and design criteria are examined. Based on the results of simulation of the current three-stage process. a design strategy for improving the process sequence is analyzed using the thick-walled pipes. Because it has a reduced process-sequence without buckling of the workpiece or overloading of tools, the new process has distinct advantages over the conventional process. Numerical results show that the newly proposed process with selected presses is the most economical way to produce the required part.

  • PDF

Statistical Process Control Procedure for Integral-Controlled Processes

  • Lee, Jaeheon;Park, Cangsoon
    • Communications for Statistical Applications and Methods
    • /
    • v.7 no.2
    • /
    • pp.435-446
    • /
    • 2000
  • Statistical process control(SPC) and engineering process control(EPC) are two strategies for quality improvement that have been developed independently. EPC seeks to minimize variability by adjusting compensatory variables in order to make the process level close to the target, while SPC seeks to reduce variability by monitoring and eliminating causes of variation. One purpose of this paper is to propose the IMA(0,1,1) model as the in-control process model. For the out-of-control process model we consider two cases; one is the case with a step shift in the level, and the other is the case with a change in the nonstationarity. Another purpose is to suggest the use of an integrated process control procedure with adjustment and monitoring, which can consider the proposed process model effectively. An integrated control procedure will improve the process control activity significantly for cases of the proposed model, when compared to the procedure of using either EPC or SPC, since EPC will keep the process close to the target and SPC will eliminate special causes.

  • PDF

Effect of Viscosity Variation on Flow Characteristic in Thixoforming Process of Semi-Solid Aluminium Alloys (반용융 알루미늄 합금의 Thixoforming 공정에서 점도의 변화가 유도특성에 미치는 영향)

  • 강충길;이유철
    • Transactions of Materials Processing
    • /
    • v.8 no.2
    • /
    • pp.188-199
    • /
    • 1999
  • Semi-Solid Forming Process(Thixoforming, Rheocasting) is a novel forming process which has some advantages compared with conventional die casting, squeeze casting and hot/cold forging. In this study. Thixoforming process was selected as analysis processing in terms of billet handling and easiness of automation process. The Thixoforming process consists of reheating process of billet, billet handling, filling inot the die cavity and solidification of SSM part. In filling process, two rheology models which were Newtonian and Non-Nettonian model (Ostwald-deWaele)were verified with experimental results. The Ostwald-deWaele model shows the good agreement to the real flow and filling phenomena in die cavity. To give a boost the economical efficiency of Thixoforming process and to ensure the good forming result, reheating device coupled die set was proposed and the initial billet temperature for system that was found from experimental resluts. This study presents an overview of application of numerical analysis for simulation of semi-solid metal forming process to reduce the lead time for development of manufacturing part in industrial field.

  • PDF

A Study on Implementation of Automobile Control Software Testing Process Based on TMMi (TMMi 기반 자동차 제어 SW 테스팅 프로세스 구축에 관한 연구)

  • Jang, Jin-Wook
    • Journal of Information Technology Services
    • /
    • v.8 no.3
    • /
    • pp.159-169
    • /
    • 2009
  • The issue of method of software testing process implementation has recently been in the spotlight in korea and some vendor make every effort to improve the software testing process through the evaluation of TMMi. The level of software process is at initial level, nevertheless, so the high quality of software is not guaranteed. This paper apply to the TMMi Level2 Assessment criteria of Automobile control software testing process. The test policy and strategy, test planning, test monitoring and control, test design and execution, test environment goal. The result need to emerge development process connection on the test policy and strategy process, test planning process etc. Also, the study analyzed the infra structure to reach the repeated level via key process area. As the result the process implementation in organization suggests the policy development and the implementation activity. Finally, the practical can refer to this paper in order to implementation the software testing process.