Subset‐Row Inequalities and Unreachability in Path‐Based Formulations for Vehicle Routing and Scheduling Problems.
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| Title: | Subset‐Row Inequalities and Unreachability in Path‐Based Formulations for Vehicle Routing and Scheduling Problems. |
|---|---|
| Authors: | Faldum, Stefan1 (AUTHOR), Gschwind, Timo2 (AUTHOR), Irnich, Stefan1 (AUTHOR) irnich@uni-mainz.de |
| Source: | Networks. Mar2026, Vol. 87 Issue 2, p111-130. 20p. |
| Subjects: | Vehicle routing problem, Mathematical inequalities, Constraint programming, Scheduling, Mathematical optimization, Algorithms |
| Abstract: | This work considers branch‐price‐and‐cut algorithms for variants of the vehicle‐routing problem in which subset‐row inequalities (SRIs) are used to strengthen the linear relaxation. SRIs often help to substantially reduce the size of the branch‐and‐bound search tree. However, their use is computationally costly because SRIs modify the structure of the respective column‐generation subproblem, which is a shortest‐path problem with resource constraints (SPPRC). Each active SRI requires the addition of a resource to the labeling algorithm that is invoked for solving the SPPRC in every iteration. In the context of time‐window constraints, the concept of unreachable customers has been used for preprocessing (time‐window reduction, arc elimination, precedence identification) as well as for improving the dominance between labels in the elementary SPPRC and its relaxations. We show that the identification of unreachable customers can also help to improve the dominance due to a modified comparison of SRI‐related resources. Computational experiments with a fully fledged branch‐price‐and‐cut algorithm for the (standard and electric) vehicle‐routing problem with time windows demonstrate the effectiveness of the approach: Overall computation times decrease; for some difficult instances, they may even be cut in half, while the required modifications of a computer implementation for combining SRIs with unreachable customers are minor. [ABSTRACT FROM AUTHOR] |
| Copyright of Networks is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
| FullText | Text: Availability: 0 |
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| Header | DbId: egs DbLabel: Engineering Source An: 191298659 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Subset‐Row Inequalities and Unreachability in Path‐Based Formulations for Vehicle Routing and Scheduling Problems. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Faldum%2C+Stefan%22">Faldum, Stefan</searchLink><relatesTo>1</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Gschwind%2C+Timo%22">Gschwind, Timo</searchLink><relatesTo>2</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Irnich%2C+Stefan%22">Irnich, Stefan</searchLink><relatesTo>1</relatesTo> (AUTHOR)<i> irnich@uni-mainz.de</i> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Networks%22">Networks</searchLink>. Mar2026, Vol. 87 Issue 2, p111-130. 20p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Vehicle+routing+problem%22">Vehicle routing problem</searchLink><br /><searchLink fieldCode="DE" term="%22Mathematical+inequalities%22">Mathematical inequalities</searchLink><br /><searchLink fieldCode="DE" term="%22Constraint+programming%22">Constraint programming</searchLink><br /><searchLink fieldCode="DE" term="%22Scheduling%22">Scheduling</searchLink><br /><searchLink fieldCode="DE" term="%22Mathematical+optimization%22">Mathematical optimization</searchLink><br /><searchLink fieldCode="DE" term="%22Algorithms%22">Algorithms</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: This work considers branch‐price‐and‐cut algorithms for variants of the vehicle‐routing problem in which subset‐row inequalities (SRIs) are used to strengthen the linear relaxation. SRIs often help to substantially reduce the size of the branch‐and‐bound search tree. However, their use is computationally costly because SRIs modify the structure of the respective column‐generation subproblem, which is a shortest‐path problem with resource constraints (SPPRC). Each active SRI requires the addition of a resource to the labeling algorithm that is invoked for solving the SPPRC in every iteration. In the context of time‐window constraints, the concept of unreachable customers has been used for preprocessing (time‐window reduction, arc elimination, precedence identification) as well as for improving the dominance between labels in the elementary SPPRC and its relaxations. We show that the identification of unreachable customers can also help to improve the dominance due to a modified comparison of SRI‐related resources. Computational experiments with a fully fledged branch‐price‐and‐cut algorithm for the (standard and electric) vehicle‐routing problem with time windows demonstrate the effectiveness of the approach: Overall computation times decrease; for some difficult instances, they may even be cut in half, while the required modifications of a computer implementation for combining SRIs with unreachable customers are minor. [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Networks is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1002/net.70014 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 20 StartPage: 111 Subjects: – SubjectFull: Vehicle routing problem Type: general – SubjectFull: Mathematical inequalities Type: general – SubjectFull: Constraint programming Type: general – SubjectFull: Scheduling Type: general – SubjectFull: Mathematical optimization Type: general – SubjectFull: Algorithms Type: general Titles: – TitleFull: Subset‐Row Inequalities and Unreachability in Path‐Based Formulations for Vehicle Routing and Scheduling Problems. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Faldum, Stefan – PersonEntity: Name: NameFull: Gschwind, Timo – PersonEntity: Name: NameFull: Irnich, Stefan IsPartOfRelationships: – BibEntity: Dates: – D: 01 M: 03 Text: Mar2026 Type: published Y: 2026 Identifiers: – Type: issn-print Value: 00283045 Numbering: – Type: volume Value: 87 – Type: issue Value: 2 Titles: – TitleFull: Networks Type: main |
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