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entropy-based measurement of manufacturing
SYSTEM complexity and its application
in scheduling
RAO Yunqing1 EFSTATHIOU
Janet2
(1. School of Mechanical Science and
Engineering, Huazhong University of Science and Technology, Wuhan
430074;
2. Department of Engineering Science,
University of Oxford, Oxford OX1 3PJ, UK)
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Abstract: The
complexity of a manufacturing system can be considered as the state of
being difficult to understand, describe, predict and control the system.
From the information, i.e. theoretic point of view, manufacturing system
complexity is defined as the expected amount of information required to
describe the state of a manufacturing system. The complexity of a
manufacturing system is investigated by two important measures, i.e.
static and dynamic. Static complexity is defined as the amount of
information required to describe the expected states of a manufacturing
system that are predicted to occur by the schedule, whereas dynamic
complexity is defined as the amount of information required to describe
the states of the manufacturing system that actually occur over time in
operation. An information-theoretic approach is applied to study the
complexity measurement of manufacturing systems, and the entropy-based
measurement models are developed. As an application, the proposed
theoretical models are used to investigate the effectiveness of
schedules for manufacturing systems, where the concepts of maximum
feasible schedule horizon and schedule adherence are introduced to
quantitatively evaluate the effectiveness of schedules. An example
demonstrates the validity of the proposed methodology.
Key words:Complexity
of manufacturing system Entropy Scheduling Effectiveness of
schedule
CLC No: F279.21
国家重点基础研究发展计划(2005CB724100)和国家自然科学基金(50105006)资助项目,Received 20050623,received
in revised form 20060109
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