This paper presents a dynamic approach to reduce tardy jobs through the integration of process planning and scheduling in a batch-manufacturing environment. The developed method aims at re-generating a schedule with f...
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This paper presents a dynamic approach to reduce tardy jobs through the integration of process planning and scheduling in a batch-manufacturing environment. The developed method aims at re-generating a schedule with fewer tardy jobs, step by step, by exploring the process plan solution space of the tardy jobs. The integrated system comprises a processplanning module, a scheduling module, and an integrator module. The processplanning module employs an optimisation approach in which the entire plan solution space is first generated and a search algorithm is then used to find the optimal plan, while the scheduling module is based on commonly used heuristics. Based on the job tardiness information of the generated schedule, the integrator module automatically issues a modification order to the process plan solution space of the tardy jobs. The processplanning and scheduling modules are then re-run to generate a new plan/schedule solution. Through this iterative process, a satisfactory schedule can be gradually achieved. The uniqueness of this approach is characterised by the flexibility of the processplanning strategy, which makes full use of the plan solution space intuitively to achieve a satisfactory schedule. Several examples are presented to confirm the efficacy and the effectiveness of the developed integration system.
An integrated approach to handle the disruption of machine breakdown is presented for the dynamic reactive scheduling problem. The proposed rescheduling approach is achieved in an iterative manner by exploring the pro...
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ISBN:
(纸本)9781424425020
An integrated approach to handle the disruption of machine breakdown is presented for the dynamic reactive scheduling problem. The proposed rescheduling approach is achieved in an iterative manner by exploring the process plan solution space of the jobs involved. An integrator module is used to link the processplanning module and scheduling module. A heuristic rule is proposed to modify solution space in terms of constraints, which are fed back to the processplanning module. The processplanning and scheduling are then re-run to obtain a new plans/schedule solution. The process continues until a satisfactory result is obtained. A case study is presented to show the effectiveness of the proposed approach.
A job shop needs to deal with a lot of make-to-order business, in which the orders are usually diverse in types but each one is small in volume. To increase the flexibility and responsiveness of the job shop in the mo...
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A job shop needs to deal with a lot of make-to-order business, in which the orders are usually diverse in types but each one is small in volume. To increase the flexibility and responsiveness of the job shop in the more competitive market, processplanning and scheduling modules have been actively developed and deployed. The functions of the two modules are usually complementary. It is ideal to integrate them more tightly to achieve the global optimization of product development and manufacturing. In this paper, a unified representation model and a simulated annealing-based approach have been developed to facilitate the integration and optimization process. In the approach, three strategies, including processing flexibility, operation sequencing flexibility and scheduling flexibility, have been used for exploring the search space to support the optimization process effectively. Performance criteria, such as makespan, the balanced level of machine utilization, job tardiness and manufacturing cost, have been systematically defined to make the algorithm adaptive to meet various practical requirements. Case studies under various working conditions and the comparisons of this approach with two modern evolutionary approaches are given. The merits and characteristics of the approach are thereby highlighted.
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