Purpose

This research proposes weighted grey relational analysis (WGRA) method to evaluate the performance of 325 multilevel dispatching rules in the wafer fabrication process.

Design/methodology/approach

The research methodology involves multilevel dispatching rule generation, simulations, WGRA and result analysis. A complete permutation of multilevel dispatching rules, including the partial orders, is generated from five basic rules. Performance measures include cycle time, move, tool idling and queue time. The simulation model and data are obtained from a wafer fab in Malaysia. Two seasons varying in customer orders and objective weights are defined. Finally, to benchmark performance and investigate the effect of varying values of coefficient, the models are compared against TOPSIS and VIKOR.

Findings

Results show that the seasons prefer different multilevel dispatching rules. In Normal season, the ideal first basic dispatching rule is critical ratio (CR) and CR followed by shortest processing time (SPT) is the best precedence pairing. In Peak season, the superiority of the rule no longer heavily relies on the first basic rule but rather depends on the combination of tiebreaker rules and on-time delivery (OTD) followed by CR is considered the best precedence pairing. Compared to VIKOR and TOPSIS, WGRA generates more stable rankings in this study. The performance of multicriteria decision-making (MCDM) methods is influenced by the data variability, as a higher variability produces a much consistent ranking.

Research limitations/implications

As research implications, the application illustrates the effectiveness and practicality of the WGRA model in analyzing multilevel dispatching rules, considering the complexity of the semiconductor wafer fabrication system. The methodology is useful for researchers wishing to integrate MCDM model into multilevel dispatching rules. The limitation of the research is that the results were obtained from a simulation model. Also, the rules, criteria and weights assigned in WGRA were decided by the management. Lastly, the distinguishing coefficient is fixed at 0.5 and the effect to the ranking requires further study.

Originality/value

The research is the first deployment WGRA in ranking multilevel dispatching rules. Multilevel dispatching rules are rarely studied in scheduling research although studies show that the tiebreakers affect the performances of the dispatching rules. The scheduling reflects the characteristics of wafer fabrication and general job shop, such as threshold and look-ahead policies.

中文翻译：

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评估晶圆制造多级调度规则的加权灰色关联分析

目的

本研究提出加权灰色关联分析(WGRA)方法来评估325个多级调度规则在晶圆制造过程中的性能。

设计/方法/方法

研究方法包括多级调度规则生成、仿真、WGRA 和结果分析。包括偏序在内的多级调度规则的完整排列是由五个基本规则生成的。性能测量包括循环时间、移动、工具空闲和排队时间。仿真模型和数据来自马来西亚的晶圆厂。定义了客户订单和目标权重不同的两个季节。最后，为了对性能进行基准测试并研究不同系数值的影响，将模型与 TOPSIS 和 VIKOR 进行比较。

发现

结果表明，季节偏好不同的多级调度规则。在正常季节，理想的第一个基本调度规则是临界比 (CR)，CR 紧随最短处理时间 (SPT) 是最佳优先级配对。在旺季，规则的优势不再主要依赖于第一条基本规则，而是依赖于决胜局规则和准时交货（OTD）的组合，然后是CR被认为是最佳的优先配对。与 VIKOR 和 TOPSIS 相比，WGRA 在本研究中产生了更稳定的排名。多标准决策 (MCDM) 方法的性能受数据可变性的影响，因为更高的可变性会产生非常一致的排名。

研究限制/影响

作为研究意义，考虑到半导体晶圆制造系统的复杂性，该应用程序说明了 WGRA 模型在分析多级调度规则方面的有效性和实用性。该方法对于希望将 MCDM 模型集成到多级调度规则中的研究人员很有用。该研究的局限性在于结果是从模拟模型中获得的。此外，WGRA 中分配的规则、标准和权重由管理层决定。最后，区分系数固定为0.5，对排名的影响有待进一步研究。

原创性/价值

该研究是首次部署WGRA对多级调度规则进行排序。尽管研究表明决胜局会影响调度规则的性能，但在调度研究中很少研究多级调度规则。调度反映了晶圆制造和一般作业车间的特征，例如阈值和超前策略。