,
Bartholomeüs Theodorus Cornelis van Rossum
Creative Commons Attribution 4.0 International license
We study the periodic assignment problem, in which a set of periodically repeating tasks must be assigned to workers within a repeating schedule. The classical efficiency objective is to minimize the number of workers required to operate the schedule. We propose a 𝒪(n log n) algorithm to solve this problem. Next, we formalize a notion of fairness among workers, and impose that each worker performs the same work over time. We analyze the resulting trade-off between efficiency and fairness, showing that the price of fairness is at most one extra worker, and that such a fair solution can always be found using the Nearest Neighbor heuristic. We characterize all instances that admit a solution that is both fair and efficient, and use this result to develop a 𝒪(n log n) exact algorithm for the fair periodic assignment problem. Finally, we show that allowing aperiodic schedules never reduces the price of fairness.
@InProceedings{vanlieshout_et_al:OASIcs.ATMOS.2025.1,
author = {van Lieshout, Rolf Nelson and van Rossum, Bartholome\"{u}s Theodorus Cornelis},
title = {{The Fair Periodic Assignment Problem}},
booktitle = {25th Symposium on Algorithmic Approaches for Transportation Modelling, Optimization, and Systems (ATMOS 2025)},
pages = {1:1--1:16},
series = {Open Access Series in Informatics (OASIcs)},
ISBN = {978-3-95977-404-8},
ISSN = {2190-6807},
year = {2025},
volume = {137},
editor = {Sauer, Jonas and Schmidt, Marie},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/OASIcs.ATMOS.2025.1},
URN = {urn:nbn:de:0030-drops-247574},
doi = {10.4230/OASIcs.ATMOS.2025.1},
annote = {Keywords: Cyclic scheduling, Fairness, Traveling Salesman Problem}
}