Computing Idle Times in Fuzzy Flexible Job Shop Scheduling

The flexible job shop scheduling problem is relevant in many different areas. However, the usual deterministic approach sees its usefulness limited, as uncertainty plays a paramount role in real-world processes. Considering processing times in the form of fuzzy numbers is a computationally affordabl...

Full description

Saved in:
Bibliographic Details
Main Authors: Pablo García Gómez, Inés González-Rodríguez, Camino R. Vela
Format: Article
Language:English
Published: MDPI AG 2025-03-01
Series:Algorithms
Subjects:
Online Access:https://www.mdpi.com/1999-4893/18/3/137
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849392660635189248
author Pablo García Gómez
Inés González-Rodríguez
Camino R. Vela
author_facet Pablo García Gómez
Inés González-Rodríguez
Camino R. Vela
author_sort Pablo García Gómez
collection DOAJ
description The flexible job shop scheduling problem is relevant in many different areas. However, the usual deterministic approach sees its usefulness limited, as uncertainty plays a paramount role in real-world processes. Considering processing times in the form of fuzzy numbers is a computationally affordable way to model uncertainty that enhances the applicability of obtained solutions. Unfortunately, fuzzy processing times add an extra layer of complexity to otherwise straightforward operations. For example, in energy-aware environments, measuring the idle times of resources is of the utmost importance, but it goes from a trivial calculation in the deterministic setting to a critical modelling decision in fuzzy scenarios, where different approaches are possible. In this paper, we analyse the drawbacks of the existing translation of the deterministic approach to a fuzzy context and propose two alternative ways of computing the idle times in a schedule. We show that, unlike in the deterministic setting, the different definitions are not equivalent when fuzzy processing times are considered, and results are directly affected, depending on which one is used. We conclude that the new ways of computing idle times under uncertainty provide more reliable values and, hence, better schedules.
format Article
id doaj-art-e4c1bf84ec0442019bfa44d28e63e349
institution Kabale University
issn 1999-4893
language English
publishDate 2025-03-01
publisher MDPI AG
record_format Article
series Algorithms
spelling doaj-art-e4c1bf84ec0442019bfa44d28e63e3492025-08-20T03:40:43ZengMDPI AGAlgorithms1999-48932025-03-0118313710.3390/a18030137Computing Idle Times in Fuzzy Flexible Job Shop SchedulingPablo García Gómez0Inés González-Rodríguez1Camino R. Vela2Department of Mathematics, Statistics and Computing, Universidad de Cantabria, 39005 Santander, Cantabria, SpainDepartment of Mathematics, Statistics and Computing, Universidad de Cantabria, 39005 Santander, Cantabria, SpainDepartment of Computer Science, Universidad de Oviedo, 33204 Gijón, Asturias, SpainThe flexible job shop scheduling problem is relevant in many different areas. However, the usual deterministic approach sees its usefulness limited, as uncertainty plays a paramount role in real-world processes. Considering processing times in the form of fuzzy numbers is a computationally affordable way to model uncertainty that enhances the applicability of obtained solutions. Unfortunately, fuzzy processing times add an extra layer of complexity to otherwise straightforward operations. For example, in energy-aware environments, measuring the idle times of resources is of the utmost importance, but it goes from a trivial calculation in the deterministic setting to a critical modelling decision in fuzzy scenarios, where different approaches are possible. In this paper, we analyse the drawbacks of the existing translation of the deterministic approach to a fuzzy context and propose two alternative ways of computing the idle times in a schedule. We show that, unlike in the deterministic setting, the different definitions are not equivalent when fuzzy processing times are considered, and results are directly affected, depending on which one is used. We conclude that the new ways of computing idle times under uncertainty provide more reliable values and, hence, better schedules.https://www.mdpi.com/1999-4893/18/3/137schedulingflexible job shopfuzzy numbersidle times
spellingShingle Pablo García Gómez
Inés González-Rodríguez
Camino R. Vela
Computing Idle Times in Fuzzy Flexible Job Shop Scheduling
Algorithms
scheduling
flexible job shop
fuzzy numbers
idle times
title Computing Idle Times in Fuzzy Flexible Job Shop Scheduling
title_full Computing Idle Times in Fuzzy Flexible Job Shop Scheduling
title_fullStr Computing Idle Times in Fuzzy Flexible Job Shop Scheduling
title_full_unstemmed Computing Idle Times in Fuzzy Flexible Job Shop Scheduling
title_short Computing Idle Times in Fuzzy Flexible Job Shop Scheduling
title_sort computing idle times in fuzzy flexible job shop scheduling
topic scheduling
flexible job shop
fuzzy numbers
idle times
url https://www.mdpi.com/1999-4893/18/3/137
work_keys_str_mv AT pablogarciagomez computingidletimesinfuzzyflexiblejobshopscheduling
AT inesgonzalezrodriguez computingidletimesinfuzzyflexiblejobshopscheduling
AT caminorvela computingidletimesinfuzzyflexiblejobshopscheduling