• Title/Summary/Keyword: Cycle time

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The Study of the Cycle Time Improvement by Work-In-Process Statistical Process Control Method for IC Foundry Manufacturing

  • Lin, Yu-Cheng;Tsai, Chih-Hung;Li, Rong-Kwei;Chen, Ching-Piao;Chen, Hsien-Ching
    • International Journal of Quality Innovation
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    • v.9 no.3
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    • pp.71-91
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    • 2008
  • The definition of cycle time is the time from the wafer start to the wafer output. It usually takes one or two months to get the product since customer decides to produce it. The cycle time is a critical factor for customer satisfaction because it represents the response time to the market. Long cycle time reflects the ineffective investment for the capital. The cycle time is very important for foundry because long cycle time will cause customer unsatisfied and the order loss. Consequently, all of the foundries put lots of human source in the cycle time improvement. Usually, we make decisions based on the experience in the cycle time management. We have no mechanism or theory for cycle time management. We do work-in-process (WIP) management based on turn rate and standard WIP (STD WIP) set by experiences. But the experience didn't mean the optimal solution, when the situation changed, the cycle time or the standard WIP will also be changed. The experience will not always be applicable. If we only have the experience and no mechanism, management will not be work out. After interview several foundry fab managers, all of the fab can't reflect the situation. That is, all of them will have an impact period after product mix or utilization varied. In this study, we want to develop a formula for standard WIP and use statistical process control (SPC) concept to set WIP upper/lower limit level. When WIP exceed the limit level, it will trigger action plans to compensate WIP Profile. If WIP Profile balances, we don't need too much WIP. So WIP level could be reduced and cycle time also could be reduced.

Impact Variables of Dump Truck Cycle Time for Heavy Excavation Construction Projects

  • Song, Siyuan;Marks, Eric;Pradhananga, Nipesh
    • Journal of Construction Engineering and Project Management
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    • v.7 no.2
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    • pp.11-18
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    • 2017
  • The cycle time of construction equipment for earthwork operations has a significant impact on project productivity. Elements that directly impact a haul vehicle's cycle time must be identified in order to accurately quantify the haul cycle time and implement strategies to decrease it. The objective of this research is to scientifically identify and quantify variables that have a significant impact on the cycle time of a dump truck used for earthwork. Real-time location data collected by GPS devices deployed in an active earthwork moving construction site was analyzed using statistical regression. External data including environmental components and haul road conditions were also collected periodically throughout the study duration. Several statistical analyses including a variance analysis and regression analysis were completed on the dump truck location data. Collected data was categorized by stage of the dump truck cycle. Results indicate that a dump truck's enter idle time, exit idle time, moving speed and driver visibility can significantly impact the dump truck cycle time. The contribution of this research is the identification and analysis of statistically significant correlations of variables within the cycle time.

A Study on Analyzing and Improving EtherCAT Cycle Time (EtherCAT Cycle Time의 성능 분석 및 향상에 관한 연구)

  • Lee, Bum-Yong;Park, Jaehyun
    • Proceedings of the Korea Information Processing Society Conference
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    • pp.463-464
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    • 2009
  • 기존 필드버스의 낮은 트래픽 전송률로 인하여 IEEE 802.3 이더넷이 필드버스의 대안으로 제시되었다. 하지만, 이더넷은 CSMA/CD 메카니즘을 사용하기 때문에 실시간 성이 떨어진다는 단점이 있다. 이러한 단점을 개선하기 위하여 EtherCAT이 개발되었다. 본 논문에서는 EtherCAT의 Cycle Time 성능을 분석하고 개선하기 위하여 M-EtherCAT을 제안한다. M-EtherCAT은 EtherCAT과 달리 각 Telegram이 Slave를 거치지 않기 때문에 EtherCAT 보다 Cycle Time의 최소 주기를 더 줄일 수 있다.

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Analysis of Optimal Kanban Cycle Time (최적 Kanban 수거 시간에 대한 분석)

  • 이상복
    • Journal of the Korean Operations Research and Management Science Society
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    • v.23 no.4
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    • pp.53-61
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    • 1998
  • In this paper, we take into consideration the optimal cycle time in a kanban system. Even though there are many studios in the literature published in the past. It is rare to fine a paper dealing with kanban cycle time. We consider manufacturing structure configured in the real field and suggest kanban cycle time for the cases of linear, tree assembled, distributed, general and mixed structures. Also we give numerical example for each structure.

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A Decision Support System for Simulation of the Container Crane Cycle Time (컨테이너 크레인 최적 운전시간의 시뮬레이션을 위한 의사결정시스템)

    • Journal of Korean Port Research
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    • v.10 no.2
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    • pp.43-50
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    • 1996
  • The purpose of this paper is to develop the cycle time simulation system for the various types of container cranes - container cranes, RMGC, RTGC, OHBC. First, the paper describes the derivation of the cycle time formula for crane simulation and the development of the simulation logic. And, the paper includes details on the design and implementation of the computer simulation system.

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State-of-practice and State-of-Art for the Project Cycle Time Reduction

  • Hong, Tae Hoon
    • Architectural research
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    • v.7 no.2
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    • pp.69-79
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    • 2005
  • There are no formal decision tools or guidelines to assist owners and contractors in choosing delivery systems and project strategies that would allow for a radical reduction in project cycle time - from the preplanning phase through project start up. Therefore, it is important to identify the state-of-practice and the state-of-art on methods of achieving radical reduction defined as a reduction of 25% or more in overall project cycle time. A comprehensive literature review, three questionnaire surveys, and the seven case studies were conducted and the data obtained from them were analyzed to establish the state-of-practice and state-of-art for project cycle time reduction techniques.

An Assignment-Balance-Optimization Algorithm for Minimizing Production Cycle Time of a Printed Circuit Board Assembly Line

  • Lee, Sang-Un
    • Journal of the Korea Society of Computer and Information
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    • v.21 no.2
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    • pp.97-103
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    • 2016
  • This paper deals with the cycle time minimization problem that determines the productivity in printed circuit board (PCB) with n components using the m placement machines. This is known as production cycle time determination problem (PCTDP). The polynomial time algorithm to be obtain the optimal solution has been unknown yet, therefore this hard problem classified by NP-complete. This paper gets the initial assignment result with the machine has minimum unit placement time per each component firstly. Then, the balancing process with reallocation from overhead machine to underhead machine. Finally, we perform the swap optimization and get the optimal solution of cycle time $T^*$ within O(mn) computational complexity. For experimental data, the proposed algorithm can be obtain the same result as integer programming+branch-and-bound (IP+B&B) and B&B.

Essence Applicability Matrices for the Reduction of Project Cycle Time

  • Hong, Tae Hoon;Son, Jae Ho
    • Architectural research
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    • v.8 no.1
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    • pp.57-68
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    • 2006
  • Global competition and reduced project life cycle ultimately puts greater performance requirements on the capital project delivery systems used to maintain competitiveness. Despite continuing improvements in delivery cycle time, business owners of facilities continue to demand greater improvements in project delivery cycle time. Therefore, it is very important to investigate the various techniques and methods leading to reduction in project cycle time and also identify the applicability of identified techniques and methods. This paper introduces reduction techniques identified through literature review (i.e, Schedule Reduction Techniques (SRTs), Management Techniques (MTs), and Construction Institute Industry (CII) Best Practices (BPs). In order to collect applicability of these techniques under different project phases (Pre-project planning (PPP), Design (D), Material Management (MM), Construction (C), and Start-up (SU)), the Essence Applicability Matrices (EAM) is used.

The Cycle Time of the Vendor in a Single-Vendor Multi-Buyers Supply Chain (단일 공급자 다수 구매자 공급체인에서 공급자주기)

  • Chang, Suk Hwa
    • Journal of the Society of Korea Industrial and Systems Engineering
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    • v.37 no.3
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    • pp.129-138
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    • 2014
  • This paper is to analyze the cycle time of the vendor in a single-vendor multi-buyers supply chain. The vendor is the manufacturer and the buyers are the retailers. The cycle time of the vendor is the elapse time from the beginning time of the production to the beginning time of the next production. The cycle time of the vendor that minimizes the total cost in a supply chain is analyzed. The cost factors are the production setup cost and the inventory holding cost of the vendor, the ordering cost and the inventory holding cost of the retailers. The cycle times of the vendor obtained with the costs of the vendor is compared with those obtained with the costs of the vendor and the retailers. Various numerical examples are tested if the cycle times of the vendor for both methods are the same.

A Study on Cycle Time and Power Saving Effect of a Hydraulic Hybrid Injection Molding Machine using a Servo Motor (서보모터를 이용한 유압 하이브리드식 사출성형기의 공정시간 및 절전효과에 관한 연구)

  • Yun, Hongsik;Kim, Sungdong
    • Journal of Drive and Control
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    • v.17 no.3
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    • pp.15-25
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    • 2020
  • The cycle time and power saving effect of a hydraulic hybrid injection molding machine using a servo motor are considered in this paper. In order to verify control characteristics, such as pressure and speed, experiments were performed with the hydraulic hybrid injection molding machine, clamping force of 110 ton. The power consumption and production cycle time of a conventional hydraulic injection molding machine were measured to compare its performances with the hydraulic hybrid injection molding machine. An injection molding machine with a clamping force of 1300 ton was used as the conventional machine, the hybrid machine was implemented by replacing its induction motors with servo motors. In the remodeled hybrid machine, experiments were performed to investigate how the displacement of the mold clamping pump affects the power consumption and production cycle time. The results showed that the production cycle time of the hybrid injection molding is similar to a conventional hydraulic injection molding machine but with a significant energy saving of about 40%.