Research

year 1999 
author Daeyoung Chung 
Keyword job shop scheduling, production planning, operation subcontract, overtime, decomposition 
Abstract Reliable and timely delivery is an important factor determining the competitive strength of a manufacturing company. In some environment, keeping due date is considered as a constraint whose violation is not permitted. However, a production plan and promised due dates usually cannot be accomplished owing to diverse reasons including insufficient production capacity and unexpected events. To cope with such problems, loads are modified using alternative routing, subcontracting, overtime work, etc. Capacity adjustments are usually considered in production planning, but the plan cannot correctly reflect the limited capacities of production resources. So the intervention of human planner is inevitable to rectify the plan, but the performance of the resulting plan is usually inferior with respect to costs because the human planner does not have proper decision support tools. To make a cost efficient plan, the capacity adjustment should be considered at scheduling level.

This paper deals with a job shop scheduling problem considering operation subcontract and overtime work. The problem has more decision variables and complex constraints than the pure job shop scheduling problem, which traditionally has been regarded as one of the most difficult combinatorial optimization problems. Due to the characteristic of the problem, decomposition and synthesis method is proposed to get the solution. First, the solution method starts with a traditional job shop scheduling problem with an objective of minimizing the violation of due date constraints. Second, the subcontract operations are repeatedly selected to reduce the remaining violation while minimizing the costs. At each iteration step, the overtime plans are modified to minimize the total cost of adjusting production capacities. Incidentally, the proposed solution methodology could also be utilized to solve an independent sub-problems of this type.

Next, a job shop scheduling problem with an objective of minimizing maximum lateness is addressed, and an optimization method and a heuristic algorithm are developed. The optimization method transforms the problem into a series of constraint satisfaction problems (CSP), and solves the CSP until an optimal solution is found. In this research, a new variable ordering / value ordering method and an improved dichotomous search method are introduced. Being implemented with an efficient constraint propagation technique, the suggested method shows superior performance than the other existing methods. The heuristic algorithm aims to find good solutions by improving the schedules obtained by widely used dispatching rules. The algorithm is designed to incrementally reduce the maximum lateness by repeatedly re-sequencing the jobs on bottleneck machines with Carlier´s algorithm. Perceiving that the jobs spend much waiting time owing to poor sequencing decisions, the algorithm is designed to select the bottleneck machine by relaxing the capacity constraint. The suggested method was shown to improve the quality of the solution more than the critical pair-wise exchange method in a very short time.

Next, a job shop scheduling problem considering operation subcontract is defined, and its solution method is suggested. The problem is decomposed into two sub-problems that are much related with each other, and so we would better not to use a sequential approach. Reflecting the relationship of the sub-problems, a solution method that deals with the sub-problems in an integrated manner is developed. In short, re-sequencing of the jobs and the selection of subcontracting operations are repeatedly conducted on bottleneck machines. To select the subcontracting operations with minimum cost, a branch and bound algorithm was developed. However, during the actual application of the algorithm, it was discovered that the maximum lateness cannot be decreased sometimes. To clear the cause of the stall and to make a way out, an algorithm that transforms the problem into a maximum flow problem is also developed. Through experiments, it is shown that the suggested solution method outperforms the conventional method and the sequential approaches.

Overtime scheduling is a difficult problem that must consider the time availability of production resources. An implicit representation method that relaxes the time availability constraint and a time-based decomposition method are used to circumvent the difficulties. As a result, the original problem can be solved by successive determination of overtime production quantity in each period. To determine the overtime quantity of a period, a linear programming model is used. The LP model considers the constraints occurred by the release time of a job and the operations planned to be subcontract.

The results of this study can be utilized to support the decision making of a human planner by generating a plan with minimum cost. Also this study may be considered as one of the first attempts to integrate the production planning problems and production scheduling problems. 
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번호 c year 제목 author
111 PhD  1995  Design Support System for the Conceptual Design of Manufacturing Databases [13] Kitae Shin 
110 PhD  1991  An Integrated Decision Support System for FMS Planning and Control Problems [11] Seongyoung Jang 
109 PhD  1994  A Study on Design of a Cooperative- Distributed Shop Floor Control System for Computer Integrated Manufacturing [19] Namkyu Park 
108 PhD  1996  An Improved Scheduling Heuristic Based on Batch Splitting Method for The Job Shop Scheduling Problem [4] Hanil Jeong 
107 PhD  1996  A Design Support System for the Process Design of Computer Integrated Manufacturing [2] Chankwon Park 
106 PhD  1997  A Study on the Integration of Process Planning and Scheduling [3] Kidong Kim 
105 PhD  1997  Computer-Aided Synthesis of the Execution Controllers for Workcells in Computer Integrated Manufacturing Systems [18] Sangkyun Kim 
104 PhD  1997  A Study on FMS Design Justification Considering Part Type Selection and Performance Evaluation Hosub Shin 
103 PhD  1997  A Study on the Integration of Loading and Scheduling in Flexible Manufacturing Systems [21] Sangbok Woo 
» PhD  1999  A Study on Job Shop Scheduling Problems considering Production Capacity Adjustment [16] Daeyoung Chung 
101 PhD  1999  A Study on the Manufacturing System State Based Scheduler using Neural Network and Simulator [20] Kitae Kim 
100 PhD  2002  Flexible Job Shop Scheduling with Multi-level Job Structures [16] Yangja Jang 
99 PhD  2003  Process Modeling and Performance Analysis Methodology toward Optimal Design of Manufacturing Systems [30] Kichang Lee 
98 PhD  2004  Ontology Development for e-Business Integration [26] Tai-Woo Chang 
97 PhD  2005  A Study on the Integration of Quality Designing and Process Control in Steel Industry [15] Jonghan Kim 
96 PhD  2005  Performance Analysis and Network Design of Supply Chain for Strategic Decision Making [14] Eoksu Sim 
95 PhD  2005  Development of an algorithm for multi-plant production plans in a supply chain [50] Sungwon Jung 
94 PhD  2008  A study on integrated production planning and strategic framework in supply chain [15] Haejoong Kim 
93 PhD  2009  A Study for Business Process Improvement Using Real-time Information of Unbalanced Work [19] Jaehyun Kong 
92 PhD  2010  Framework for Integrative SRM System and Collaboration Scorecard [26] Jongkyoung Park 
91 PhD  2007  A Study on MRP Process Improvement in a Grid Enabled APS [2] file Hyoung-Gon Lee 
90 PhD  2010  Enhancing Flexibility and Responsiveness in Sales Order Management [54] Mokmin Park 
89 PhD  2013  Price of Simplicity under Congestion: On the Revenue and Pricing Schemes in the Telecommunication Industry [58] file Dongmyung Lee 
88 PhD  2013  A study on production scheduling problems considering differential electricity pricing and distributed generations Jun Young Moon 
87 PhD  2014  Multi-level job scheduling in a flexible discrete-part production environment Hong Bum Na 
86 PhD  2014  A study on integrative decision-making system for reconfigurable manufacturing cells Jin Wu Seo 
85 MS  1994  A Study on Distributed Shop Floor Control of Flexible Manufacturing Systems [4] Daeyoung Chung 
84 MS  1994  A Study on Development of a Knowledge Based Scheduler and Knowledge Acquisition through Simulation [1] Kitae Kim 
83 MS  1995  A Study on knowledge Acquisition for Simulation-based Scheduling Expert System [1] Soohyun Lee 
82 MS  1995  A study on intelligent dispatching strategy in Automated Manufacturing Systems [5] Seongwoo Lee 
81 MS  1988  A Simulation Study on Operating Rules of FMS Considering Tool Change Byunghoon Yoo 
80 MS  1988  Development of a Classification and Coding System through Fuzzy Sets Approach [1] Namkyu Park 
79 MS  1988  A Study on The Machine-Part Group Formation for FMS Planning and Operation Jaeyoon Kim 
78 MS  1989  A Study on the Computer and Database Location of Distributed Computer Systems in FMS [1] Kilsup Yang 
77 MS  1989  An FMS Planning Algorithm Considering Tool Magazine Capacity and Alternative Routings [6] Chankwon Park 
76 MS  1989  A Mathematical Decision Making Model for Real-Time Scheduling of an FMS Jonghan Kim 
75 MS  1995  An Object-Oriented Framework for the Implementation of Distributed Shop Floor Control in FMS [2] Kyungsuk Lee 
74 MS  1995  A study on Real-Time Collection of Shop Floor Data Using Speech Recognition [2] Namjoo Kim 
73 MS  1995  A Study on the Group Scheduling Problem with Sequence-dependent Set-up Times in a Multi-stage Cellular Manufacturing Systems Jaesoo Shim 
72 MS  1990  A Fuzzy Linguistic Approach to the Part Selection Problem in FMS [1] Yoosuk Hong 
71 MS  1990  A Study on Data Allocation Problems for Distributed Database Design [2] Kitae Shin 
70 MS  1991  A Study on Scheduling Problem of Hierarchically Structured Products in FMS [1] Hanil Jeong 
69 MS  1991  A Study on Performance Evaluation of Production Plan for FMS Using Queueing Network [1] Sangbok Woo 
68 MS  1991  A Study on the Layered Architecture for the Control of FMS Cells Hosub Shin 
67 MS  1991  A Study on Image Processing and CAD - Vision System Interface of Manufactured Parts [1] Kidong Kim 
66 MS  1992  A Study on Production Planning Problems in a Flexible Machining and Assembly System [1] Sukang Lee 
65 MS  1992  Event-Driven On-Line Operational Control of Flexible Manufacturing Systems Jonghun Park 
64 MS  1992  A Decision Support System for A Machine Specifications in Design of An FMS [6] Youngkwan Ko 
63 MS  1993  A Study on the Computer-Aided Process Planning for Rotational Parts Considering Machine Status [1] Sungbum Chun 
62 MS  1993  A Comparative Analysis of Production Control Policies under Production Uncertainty [5] Janghan Lee