• Title, Summary, Keyword: scheduling

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Scheduling and simulation for FMC systems (FMC 시스템의 스케쥴링 및 시뮬레이션)

  • 서기성;이노성;안인석;박승규;이규호;우광방
    • 제어로봇시스템학회:학술대회논문집
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    • pp.370-375
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    • 1992
  • This paper deals with the scheduling and simulation for FMC(Flexible Manufacturing Cells). In order to achieve CIM, there is a critical need to link factory level and machine level. The primary functions performed by this link for all jobs issued to the shop floor and cell include short-term scheduling and dynamic operational scheduling. Here, hierarchical control structure is introduced to define these functions. And Intelligent scheduling through expert module is adopted for efficiency of FMC operation. Computer simulation reveals that expert scheduling method is better than heuristics in various performance index.

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A Study on the Optimal Scheduling in n/m Flow Shop Scheduling : the Measure of Performance (n/m Flow Shop Scheduling에 있어서 최적 Scheduling에 관한 연구 - 평가척도를 중심으로 -)

  • 이근희;김준홍
    • Journal of the Society of Korea Industrial and Systems Engineering
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    • v.4 no.4
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    • pp.1-13
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    • 1981
  • This paper analyses the efficiency of performance measures from the point of total cost on the accuracy of due date around various measures of performance be in mainly use in the flow shop scheduling theory. For this purpose, complete enumeration method for small problems seems to be the only possible means of evaluation and analysis. Using of the above technique, calculates the 800 Scheduling Problems, and represents it by the cumulative distributions.

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Evaluation Of The Content-Based Packet Scheduling Policies On The Multithreaded Multiprocessor Network System

  • Yim Kangbin
    • Proceedings of the IEEK Conference
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    • pp.39-41
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    • 2004
  • In this paper, I propose a thread scheduling policy for faster packet processing on the network processors with multithreaded multiprocessor architecture. To implement the proposed policy, I derived several basic parameters related to the thread scheduling and included a new parameter representing the packet contents and the features of the multithreaded architecture. Through the empirical study using a network processor, I proved the proposed scheduling ploicy provides better throughput and load balancing compared to the generally used thread scheduling policy.

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An Watch Duty Scheduling by using Heuristic focused on Korea Navy Ship (휴리스틱을 이용한 초계함급 함정의 정박당직근무 일정계획)

  • Jang, Yeong-Cheon;Jun, Geon-Uk
    • Journal of the military operations research society of Korea
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    • v.31 no.2
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    • pp.60-74
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    • 2005
  • The main purpose of this study is to develop an watch duty scheduling focused on Korea Navy Ship, PCC class, in port. The watch duty scheduling is a type of a scheduling problem which both considers the readiness of the ship and fair duty for each person. In this study, we analyzed the personal ability and military occupational speciality and developed a manpower scheduling by using heuristic. We find an efficient and effective watch duty schedule which improved results.

Development of an Extended EDS Algorithm for CAN-based Real-Time System

  • Lee, Byong-Hoon;Kim, Dae-Won;Kim, Hong-Ryeol
    • 제어로봇시스템학회:학술대회논문집
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    • pp.60.3-60
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    • 2001
  • Usually the static scheduling algorithms such as DMS(Deadline Monotonic Scheduling) or RMS(Rate Monotonic Scheduling) are used for CAN scheduling due to its ease with implementation. However, due to their inherently low utilization of network media, some dynamic scheduling approaches have been studied to enhance the utilization. In case of dynamic scheduling algorithms, two considerations are needed. The one is a priority inversion due to rough deadline encoding into stricted arbitration fields of CAN. The other is an arbitration delay due to the non-preemptive feature of CAN. In this paper, an extended algorithm is proposed from an existing EDS(Earliest Deadline Scheduling) approach of CAN scheduling algorithm having a solution to the priority inverstion ....

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A Study on Loading and Scheduling of Assembly Block in Shipbuilding (조선산업에서의 블록 배량계획과 일정계획에 관한 연구)

  • Kim, Ki-Dong;Jeon, In-Woo;Kim, Tae-Hyeon
    • Journal of Industrial Technology
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    • v.22 no.B
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    • pp.61-70
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    • 2002
  • The shipbuilding scheduling has many possible alternatives because of its long time horizon and a lot of jobs, so it is required that the scheduling system can generate and search feasible alternatives rapidly. The scheduling in the assembly shop is initiated by allocating, namely loading, the assembly blocks to each shop. In this step, the resource capacities (such as available man/hour, available crane) of each shop must be considered. The result of loading without above consideration can make the scheduling result based on that infeasible or worse one. In this paper, we developed the optimal scheduling system of shipbuilding, specifically for loading and scheduling of assembly block, using ILOG Solver/Scheduler. ILOG Solver/Scheduler is a general-purposed commercial software which supports to find a feasible or optimal solution using object oriented technique and constraints satisfaction programming, given constraints and objectives. Also, in order to enhance the system performance, we conducted various experiments of ILOG search strategies. The experimental results showed that the impact of search strategies is significant.

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Knowledge Acquisition on Scheduling Heuristics Selection Using Dempster-Shafer Theory(DST) (Dempster-Shafer Theory를 이용한 스케듈링 휴리스틱선정 지식습득)

  • Han, Jae-Min;Hwang, In-Soo
    • Journal of Intelligence and Information Systems
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    • v.1 no.2
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    • pp.123-137
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    • 1995
  • Most of solution methods in scheduling attempt to generate good solutions by either developing algorithms or heuristic rules. However, scheduling problems in the real world require considering more factors such as multiple objectives, different combinations of heuristic rules due to problem characteristics. In this respect, the traditional mathematical a, pp.oach showed limited performance so that new a, pp.oaches need to be developed. Expert system is one of them. When an expert system is developed for scheduling one of the most difficult processes faced could be knowledge acquisition on scheduling heuristics. In this paper we propose a method for the acquisition of knowledge on the selection of scheduling heuristics using Dempster-Shafer Theory(DST). We also show the examples in the multi-objectives environment.

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Resource Constrained Dynamic Multi-Projects Scheduling Based by Constraint Programming (Constraint Programming을 이용한 자원제약 동적 다중프로젝트 일정계획)

  • Lee, Hwa-Ki;Chung, Je-Won
    • IE interfaces
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    • v.12 no.3
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    • pp.362-373
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    • 1999
  • Resource Constrained Dynamic Multi-Projects Scheduling (RCDMPS) is intended to schedule activities of two or more projects sequentially arriving at die shop under restricted resources. The aim of this paper is to develop a new problem solving method for RCDMPS to make an effect schedule based by constraint programming. The constraint-based scheduling method employs ILOG Solver which is C++ constraint reasoning library for solving complex resource management problems and ILOG Schedule which is a add-on library to ILOG Solver dedicated to solving scheduling problems. And this method interfaces with ILOG Views so that the result of scheduling displays with Gantt chart. The scheduling method suggested in this paper was applied to a company scheduling problem and compared with the other heuristic methods, and then it shows that the new scheduling system has more preference.

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Development of PC-based PVC scheduling system connected with ERP system

  • Kang, Min-Gu;Kang, Soo-Kil;Lee, Ho-Kyung;Park, Sun-Won
    • 제어로봇시스템학회:학술대회논문집
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    • pp.945-949
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    • 2004
  • These days there are so many scheduling systems or softwares. But only few scheduling systems have succeeded in the market. In spite of powerful engine and functions, those systems have difficulties to be applied in real processes. In real processes, there are various constraints caused by physical or systematical environments of plants. Those constraints are too many to be handled in the system. This problem makes it difficult for the system to represent the details of processes. In order to resolve this problem, we have developed a specialized scheduling system for a target process. The system could be developed by the experts for target process and researchers for scheduling. In this study, a scheduling system for PVC process has been developed as an MILP (Mixed integer linear programming) model and coded in $Fortran^{TM}$. The scheduling system has been applied to two processes, which have different characteristics. Simulation results indicate that the profit of the target process can be increased by about 5% by implementing the scheduling system.

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An Algorithm for Scheduling Repetitive Projects with Resource Continuity and Different Batch Sizes

  • Shim, Euysup;Yoo, Wi Sung
    • Journal of the Korea Institute of Building Construction
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    • v.13 no.6
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    • pp.565-578
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    • 2013
  • Batch production is common in repetitive construction projects, and it is not unusual for different batch sizes to be used by contractors in one project. While several scheduling methods, such as the Linear Scheduling Method (LSM) and the Repetitive Scheduling Method (RSM) have been proposed and used, no mathematical method for repetitive construction projects has been developed, and it is difficult to consider different batch sizes with the existing methods. An original mathematical algorithm for scheduling repetitive projects with different batch sizes is proposed in this study. This algorithm is illustrated with assumptions of resource continuity and single path in a project and introduces new terms, control batch and critical batch. The algorithm logics and mathematical equations are validated by comparison with the outcomes from a graphical scheduling approach through a simple and practical hypothetic project. As a result, it is expected that the proposed algorithm can be easily adapted and extended to computer software for scheduling, and can be a starting point for research on batch size management in repetitive construction projects.