A study on robust scheduling method to reduce delay risk under uncertainty

2022 Fiscal Year Final Research Report

• Project/Area Number: 18K04614
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 25010:Social systems engineering-related
• Research Institution: Osaka Metropolitan University (2022); Osaka Prefecture University (2018-2021)
• Principal Investigator: Morizawa Kazuko 大阪公立大学, 大学院工学研究科, 教授 (60220050)
• Co-Investigator(Kenkyū-buntansha): 平林 直樹 大阪公立大学, 大学院情報学研究科, 准教授 (80199091)
• Project Period (FY): 2018-04-01 – 2023-03-31
• Keywords: スケジューリング / 機械故障 / 遅延リスク / ロバスト性

Outline of Final Research Achievements

Unexpected events, such as machine breakdowns, occur on a daily basis in production plants and are perceived as inevitable. If a machine breakdown occurs while production operations are being implemented based on a carefully planned schedule, there is a high possibility that the resulting small work delay will propagate, increasing the risk of major delays.
In this research, assuming that rescheduling will not be performed even if an unexpected event occurs, we addressed the development of a scheduling method to obtain a robust schedule that is expected to be less affected by work delays at the planning stage. First, for flow-shop, we proposed an index to evaluate robustness of a schedule that focuses on the slack of each job, and then, extended it to be applicable to job-shop. Numerical experiments show that the proposed index is useful for generating robust schedules.

Free Research Field

経営工学

Academic Significance and Societal Importance of the Research Achievements

製造業はリードタイム短縮・短納期化を目指して非常にタイトなスケジュールの下でものづくりを行っている。このため、生産期間中に機械故障に代表される不確実事象が発生し、事前に綿密に計画されたスケジュールに即した生産が実施できない事態に陥ると、一転して大幅な加工遅延を起こしてしまう場合が多い。本研究課題は、生産性が高く、かつ不確実事象による加工遅延を引き起こしにくい頑健なスケジュールのもとで生産を行うことを推奨するロバストスケジューリングにおいて課題となっていた、スケジュールの頑健性をより正確に評価するための指標を提案したものである。