Predicting Due Dates under Various Combinations of Scheduling Rules in a Wafer Fabrication Factory

Sha, D.Y.,Storch, Richard,Liu, Cheng-Hsiang Korean Institute of Industrial Engineers 2003 Industrial Engineeering & Management Systems Vol.2 No.1

In a wafer fabrication factory, the completion time of an order is affected by many factors related to the specifics of the order and the status of the system, so is difficult to predict precisely. The level of influence of each factor on the order completion time may also depend on the production system characteristics, such as the rules for releasing and dispatching. This paper presents a method to identify those factors that significantly impact upon the order completion time under various combinations of scheduling rules. Computer simulations and statistical analyses were used to develop effective due date assignment models for improving the due date related performances. The first step of this research was to select the releasing and dispatching rules from those that were cited so frequently in related wafer fabrication factory researches. Simulation and statistical analyses were combined to identify the critical factors for predicting order completion time under various combinations of scheduling rules. In each combination of scheduling rules, two efficient due date assignment models were established by using the regression method for accurately predicting the order due date. Two due date assignment models, called the significant factor prediction model (SFM) and the key factor prediction model (KFM), are proposed to empirically compare the due date assignment rules widely used in practice. The simulation results indicate that SFM and KFM are superior to the other due date assignment rules. The releasing rule, dispatching rule and due date assignment rule have significant impacts on the due date related performances, with larger improvements coming from due date assignment and dispatching rules than from releasing rules.

신경망을 이용한 공정선택규칙 선정에 관한 연구

이형국 동의공업대학 1999 論文集 Vol.25 No.1

To schedule a job shop, the first task is to select an appropriate dispatching rule. Because of the complexity of scheduling problems, general algorithmic approach sufficient for solving all scheduling problems has not been developed yet. Most scheduling systems offer multiple alternative algorithms to various circumstances, therefor experienced of human scheduler are needed to select the appropriate dispatching rules for these systems. To select the dispatching rule, this paper discusses the use of neural networks. For a given workstation, various situation a simulated to identify the best dispatching rule. The dispatching rule selection system consist of three modules(a preprocessor, a neural network, and a off-line training program). The preprocessor generates an input vector for neural network based on current workstation status. The neural network is responsible for identifying promising dispatching rule based on current workstation status. The neural network structure consists of 8 sub-networks, and each sub-network consist of three layers of neurons(an input layer, an output layer, and a hidden layer). The off-line training program train a neural network with workstation status data and dispatching rules. Research results have shown great potential in using a neural network replaced with human scheduler in selecting an appropriate dispatching rule.

RTE 실현을 위한 Rule기반 지능형 생산 시스템 설계 및 구현

이위주 ( Wee Joo Lee ),정석재 ( Suk Jae Jeong ) ㈜엘지씨엔에스 2007 Entrue Journal of Information Technology Vol.6 No.1

본 연구에서는 제조기업의 RTE 실현을 위한 방안으로, FMS(Flexible Manufacturing System) 환경의 생산시스템을 대상으로 지능형 생산 제어 시스템을 설계 및 구현하는 데 그 목적이 있다. 본 연구에서 개발되는 시스템은 업무담당자들의 경험과 노하우 및 기존에 잘 알려진 Dispatching Rule들을 바탕으로 효율적인 생산계획을 위한 Rule들을 정의하여 Rule base를 구축하고, 생산 프로세스상에 발생하는 예외 상황을 해결하거나, 대기작업의 기계 할당에 있어서 실시간 효율적으로 의사결정하는 것을 돕는다. 뿐만 아니라, 생산 목표치와 현재 공정상황에 대하여 Fuzzy 기반의 추론 과정을 통해 가장 적합한 Dispatching Rule를 추론하여 생산공정에 적용할 수 있도록 한다. 개발되는 시스템은 Rule 기반 구축 과정을 따라 진행되었으며, 구성요소로는 크게 Rule Base와 데이터 베이스, 그리고 추론 엔진 및 모니터링 모듈이며, 데이터 베이스는 가공품의 종류 및 가공시간 등 시스템 전반에 대한 정보를 기록하는 정적인 데이터와 규칙을 선정하기 위한 현재 상황을 기록하는 동적인 데이터로 구성되고, Rule Base는 가공품의 기계 선택 Rule과 동적 할당 규칙을 결정하는 Rule들로 포함하고 있다. 본 연구는 향후, 기존 의사결정 방법론과의 비교 및 상황별 최적 규칙 조합을 찾는 연구가 진행 된다면, 기존에 생산 프로세스 상에서 의사결정을 위해 발생한 시간 지연을 최대한 단축함으로써 RTE 실현을 위한 기업의 비즈니스 모델로 자리잡을 수 있을 것으로 기대된다. This paper aims to design and develop the intelligent production control system under the FMS(Flexible Manufacturing System) Environment for the realizing the RTE of Manufacturing Cooperations. The developed System in this study defines the rules and design the rule base for the efficient production planning based on the knowledge and know-how of workers and well-known dispatching rules. This helps to solve the unregulaer status on the production process and determine the decision making for the machine assignment of queuing jobs in real time. Also, it enables to apply the most appreciate dispatchgin rule to the production process considering both of the production goals and current status using the fuzzy based inference process. The rule based system consists of rule base, data base, inference engine, and monitoring module. Database includes static data which records the information of system status such as the type of jobs, their processing time etc. Rule base is composed of the rules for the machine selection of jobs and the dynamic dispatching rule selection under the current status. In future, it is expected to be one of the business models for the RTE realization by the maximum reduction of delay time for the decision making on the precious production system through the rearch the comparion analysis among the existing decision making methods and the optimal combination of rules under the various environments.

Job Shop 일정계획의 성능 향상을 위한 할당규칙의 정보

배상윤(Sang-Yun Bae) 한국산업경영시스템학회 2006 한국산업경영시스템학회지 Vol.29 No.4

  This study presents the new dispatching rules for improving performance measures of job shop scheduling related to completion time and due dates. The proposed dispatching rule considers information, which includes the comparison value of job workload, work remaining, operation time, and operation due dates. Through computer experiments, the performance of the new dispatching rules is compared and analyzed with the existing rules. The results provide a guidance for the researchers to develop new dispatching rules and for practitioners to choose rules of job shop scheduling.

패밀리 기반 배정의 적용 위치에 대한 연구

징하오(Hao Jing),성리쥐안(Lijuan Sheng),곽춘종(Choonjong Kwak) 한국생산관리학회 2021 한국생산관리학회지 Vol.32 No.2

패밀리 기반 배정 규칙은 준비(setup) 과정에 대한 소요 시간을 줄여 시스템 성과를 향상시킨다. 다른 한편으로는 작업 현장에서 패밀리 기반 배정의 적용 위치가 패밀리 기반 배정 규칙의 성과에 영향을 끼칠 수 있다. 그러나 지금까지 패밀리 기반 배정의 적용 위치를 다룬 연구는 매우 드물었다. 본 논문은 패밀리 기반 배정 규칙과 그 적용 위치를 고려한 새로운 생산 통제 문제를 다룬다. 본 연구는 먼저 이 문제를 해결하기 위한 의사결정 체계를 설명한다. 패밀리 기반 배정 규칙과 그 적용 위치에 대한 연구는 2단계 흐름 공정(two-stage flow shop)에서 시뮬레이션 모델링 및 통계 분석을 통해 수행된다. 동시에 몇 가지 중요한 요인이 시스템 성과에 미치는 영향도 조사한다. 본 연구에서는 패밀리 기반 배정 규칙과 관련하여 서로 다른 적용 위치에 따른 성과 차이를 고찰한다. 패밀리 기반 배정의 적용 위치가 가변적일 때, 본 연구 결과는 패밀리 기반 배정 규칙을 효율적으로 적용하기 위한 통찰력을 제공한다. Family-based dispatching rules reduce setup time and improve system performance. However, few studies have examined how the location of family-based dispatching rules can impact their performance on a shop floor. This study addressed a new production control problem of family based dispatching rules and their application locations using a decision-making framework at a two-stage flow shop. This study explored the effects of several important factors on the system performance using statistical analysis and simulation modeling. This research also compared the performance differences arising from different locations for family-based dispatching. This paper’s results offer insights into the optimal placement of family-based dispatching rules.

색도 및 색순에 따른 그라비아 인쇄 공정의 작업 순서 결정 규칙

배재호(Jae-Ho Bae) 한국산업경영시스템학회 2020 한국산업경영시스템학회지 Vol.43 No.3

This paper presents a method to measure the similarity of assigned jobs in the gravure printing operation based on the chromaticity and color sequence, and order the jobs accordingly. The proposed dispatching rule can be used to fulfill diverse manufacturing site requirements because the parameters can be adjusted to prioritize chromaticity and color sequence. In general, dispatching rules either ignore the job-changing time or require that the time be clearly defined. However, in the gravure printing operation targeted in this study, it is difficult to apply the general dispatching rule because of the difficulties in quantifying the job-changing time. Therefore, we propose a method for generalizing assignment rules of the job planner, allocating relative similarity among assigned jobs, and determining the sequence of jobs accordingly. Chromaticity priority is determined by the arrangement of the color assignments in the printing operation; color sequence priority is determined by the addition, deletion, or change in a specific color sequence. Finally, the job similarity is determined by the dot product of the chromaticity and color sequence priorities. Implementation of the proposed dispatching rule at an actual manufacturing site showed the planner present the same job order as that obtained using the proposed rule. Therefore, this rule is expected to be useful in industrial sites where clear quantification of the job-changing time is not possible.

Dispatching Rule에 기반한 능동 위상 배열 다기능 레이더의 빔 스케줄링 기법

노지은(Ji-Eun Roh),안창수(Chang-Soo Ahn),김선주(Seon-Joo Kim) 한국전자파학회 2012 한국전자파학회논문지 Vol.23 No.1

능동 위상 배열레이더(AESA radar: Active Electronically Scanned Array radar)는 전자적으로 빔을 조향함으로써 빔 조향 시간이 비약적으로 빨라져, 기존의 기계식 빔 조향 레이더에 비해 레이더에서 수행할 수 있는 다중 임무처리 능력이 크게 향상되었다. 이러한 다중 임무 처리 능력을 최대화하면서 레이더의 전체 성능을 향상하기 위해, 레이더에 주어진 시간, 에너지, 처리 능력 등의 한정된 자원을 실시간으로 효율적으로 관리, 운용할 수 있는 레이더 자원 관리 기술의 중요성이 크게 대두되었다. 그 중 레이더 빔 스케줄링 기술은 레이더 자원 관리의 핵심적인 요소라 할 수 있다. 본 논문에서는 레이더 빔 스케줄링을 위한 다양한 dispatching rule을 비교 분석하고, 특히 빔의 처리 시간 지연 정도에 따라 SPF(Shortest Processing time First)와 ERF(Earliest Request time First)를 차등적으로 적용하여 빔의 우선 순위를 정하는 dispatching rule을 제안, 그 성능의 우월성을 입증하였다. AESA radar is able to instantaneously and adaptively position and control the beam, and such adaptive beam pointing of AESA radar enables to remarkably improve the multi-mission capability, compared with mechanically scanned array radar. AESA radar brings a new challenges, radar resource management(RRM), which is a technique efficiently allocating finite resources, such as energy and time to each task in an optimal and intelligent way. Especially radar beam scheduling is the most critical component for the success of RRM. In this paper, we proposed the several dispatching rules for radar beam scheduling, and compared the performance on the multi-function radar scenario. We also showed that the dispatching rule which differently applying SPF(Shortest Processing time First) and ERF(Earliest Request time First) according to beam processing latency is the most efficient.

電子商去來 시대에 있어서의 契約의 成立 時期 — 發信主義의 修正의 필요성을 중심으로 —

이종근 경북대학교 법학연구원 2011 법학논고 Vol.0 No.37

계약은 원칙적으로 청약과 승낙이라는 두 개의 의사표시가 합치함으로써 성립한다. 즉, 청약의 의사표시를 수령한 자가 청약과 내용적으로 합치하는 승낙의 의사표시를 함으로써 계약이 성립한다. 그러나 이러한 계약의 성립시점을 놓고 첨예하게 의견이 대립한다. 예컨대, 우리 민법 제531조는 승낙의 의사표시에 대하여 발신주의의 입장을 취하고 있는 반면에 제528조 제1항과 제529조는 도달주의를 전제로 하고 있어서 조화로운 해석이 쉽지 않다. 그러나 우리 전자거래기본법 제6조는 전자문서의 경우에 의사표시의 도달시점을 분명하게 규정하고 있다. 영국법원이 계약의 성립에 있어서 승낙의 의사표시를 발신한 때에 승낙의 효력 발생을 인정할 것인가 아니면 도달한 때에 인정할 것인가 하는 문제에 최초로 직면한 것이 1800년대 초였다. 그 이후 발신주의가 영국과 미국에서 계약의 성립에 있어서 승낙의 의사표시의 효력발생시기를 정하는 원칙으로서의 지위를 점하게 되었다. 오늘날의 계약환경은 발신주의를 성립시켰던 Adams v. Lindsell 사건 당시와는 완전히 다르다. 실제로 20년 전의 세계와 오늘의 세계도 완전히 다른 것이 현실이다. 기술적 변혁으로 인하여 인터넷시대의 계약법 분야에는 새로운 법원리가 정립될 필요성이 제기되고 있다. 물론 이러한 법원리는 전자기술적 의사소통방식 뿐 아니라 예전의 전통적인 의사소통방식에 의한 계약까지 포괄할 수 있는 법원리이어야 함은 물론이다. 따라서 옳든 그르든 발신주의에 의하여 지배되었던 계약, 즉 우편을 이용하는 등 非 전자식 의사소통방식을 통하여 체결되는 계약의 경우에도 이제는 도달주의가 적용되어야 할 필요가 있다는 것이 이 글의 요지이다. Contract formation needs meeting of two minds, namely offer and acceptance. A contract is formed when the offeree accepts the exact offer made by offeror. However, contract formation involves a difficult problem. For example, regarding the Korean civil law, there is a sharp conflict of opinion in harmonious interpretation of art. 531 and art. 528①, 529. However, in case of electronic documents, art. 6 of the Korean “Framework Act on Electronic Commerce” articulates the moment of receipt of offer or acceptance(Willensklerung). It was early 1800s when English courts were faced with the question of whether to make an acceptance valid at dispatch or at receipt in the communication over long distances. Hence the “mailbox” rule, also termed the dispatch rule, became the settled doctrine not only in England but also in the United States. The theme of this article is focused on the modern communication having created a world in which there is no indifference between the dispatch and receipt rules. The world today is completely different from that of the court in Adams v. Lindsell case, indeed, it is wholly different even from the world of a few decades ago. Therefore, these days, technological innovation sparks a need for new legal rules, having generated a need for new legal rules to govern even old traditional technologies. Consequently, I can say, the substance of this article is that contracts formed through the use of traditional postal mail(non-instantaneous communication) and other state of the art technologies, whether or not governed by the dispatch rule in the past, should now be governed by receipt rule.

Wafer FAB 의 납기 달성 향상을 위한 연구

안의국(Euikoog Ahn),장대순(Dae Soon Chang),박상철(Sang C. Park) (사)한국CDE학회 2015 한국 CAD/CAM 학회 학술발표회 논문집 Vol.2015 No.동계

In this paper we describe dispatching rules to improve on time delivery in semiconductor wafer FAB. This is accomplished by filtering method for global due date and local due date. First filtering factor is an attempt to optimize on time delivery from a global point of view. If queue lot is not satisfy global due date, the lot can be filtering and it gives high priority. Second filtering factor is an attempt to optimize the on time delivery from a local point of view. Second filtering factor focuses on waiting time of queue lot in current step. If waiting time of queue lot is more delay than wait TAT, the lot can be filtering and it gives high priority. For verify the performance, we developed a simulation model by modifying MIMAC6, and conducted simulation with SEEPLAN® developed by the VMS solutions. The simulation results demonstrate that the proposed dispatching rules such as achieves a better on time delivery than existing classical dispatching rules.

Research on the WIP-based Dispatching Rules for Photolithography Area in Wafer Fabrication Industries

Lin, Yu-Hsin,Tsai, Chih-Hung,Lee, Ching-En,Chiu, Chung-Ching The Korean Society for Quality Management 2007 The Asian Journal on Quality Vol.8 No.2

Constructing an effective production control policy is the most important issue in wafer fabrication factories. Most of researches focus on the input regulations of wafer fabrication. Although many of these policies have been proven to be effective for wafer fabrication manufacturing, in practical, there is a need to help operators decide which lots should be pulled in the right time and to develop a systematic way to alleviate the long queues at the bottleneck workstation. The purpose of this study is to construct a photolithography workstation dispatching rule (PADR). This dispatching rule considers several characteristics of wafer fabrication and influential factors. Then utilize the weights and threshold values to design a hierarchical priority rule. A simulation model is also constructed to demonstrate the effect of the PADR dispatching rule. The PADR performs better in throughput, yield rate, and mean cycle time than FIFO (First-In-First-Out) and SPT (Shortest Process Time).