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Concerning Workload Control and Order Release: The Pre‐Shop Pool Sequencing Decision
Author(s) -
Thürer Matthias,
Land Martin J.,
Stevenson Mark,
Fredendall Lawrence D.,
Godinho Filho Moacir
Publication year - 2015
Publication title -
production and operations management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.279
H-Index - 110
eISSN - 1937-5956
pISSN - 1059-1478
DOI - 10.1111/poms.12304
Subject(s) - tardiness , workload , computer science , selection (genetic algorithm) , control (management) , operations research , order (exchange) , build to order , process (computing) , decision rule , job shop , operations management , production (economics) , job shop scheduling , flow shop scheduling , business , computer network , engineering , economics , machine learning , microeconomics , routing (electronic design automation) , finance , artificial intelligence , operating system
Every production planning concept that incorporates controlled order release will initially withhold jobs from the shop floor and create a pre‐shop pool. Order release is a key component of the Workload Control concept that aims to maintain work‐in‐process within limits while ensuring due dates are met. Order release includes two decisions: (i) a sequencing decision that establishes the order in which jobs are considered for release; and, (ii) a selection decision that determines the criteria for choosing jobs for release. While selection has received much research attention, sequencing has been largely neglected. Using simulation, this study uncovers the potential for performance improvement in the sequencing decision and improves our understanding of how order release methods should be designed. Although most prior studies apply time‐oriented sequencing rules and load‐oriented selection rules, analysis reveals that load balancing considerations should also be incorporated in the sequencing decision. But an exclusive focus on load balancing is shown to increase mean tardiness and, paradoxically, require high workloads. A new sequencing rule is developed that only balances loads when multiple orders become urgent. It avoids high mean tardiness and allows the shop to operate at a low workload level. At the same time, the percentage tardy is reduced by up to 50% compared to a purely time‐oriented rule. The findings have implications not only for Workload Control but for any concept that features order release control, such as Con WIP and Drum‐Buffer‐Rope.