CP-WSP: A Declarative CP-SAT Framework for Configurable Multi-Constraint Workforce Scheduling
Abstract
Workforce scheduling is an NP-hard combinatorial optimization problem requiring simultaneous satisfaction of labor regulations, coverage requirements, employee preferences and operational objectives. Existing CP formulations typically model simplified instances with 6-12 constraints at shift-level granularity and critically lack explicit support for: mandatory break scheduling with midpoint placement control; acuity weighted workload equity; sub-shift temporal granularity enabling demand-driven staffing; inter-week schedule stability; and cross-midnight shift patterns common in 24-hour operations. This paper presents CP-WSP: a declarative CP-SAT framework enforcing 14 hard constraints as mathematically inviolable requirements (zero regulatory violations by construction) while optimizing 15 soft objectives through a unified weighted penalty function -- all configurable via a JSON specification with no code changes required. Key contributions include: a shift-window variable decomposition enabling mandatory break scheduling with centrality control; acuity-weighted workload equity; multi-granularity temporal resolution from 30 minutes to 2 hours; inter-week schedule stability; a grid-offset preprocessing technique for cross-midnight shifts; and a reproducible 36-configuration benchmark suite for community comparison. Evaluated on INRC-II benchmarks at both hourly and shift-level granularity and on 36 synthetic configurations.
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BibTeX
@misc{patel2026cpwsp,
title = {{CP-WSP: A Declarative CP-SAT Framework for Configurable Multi-Constraint Workforce Scheduling}},
author = {Vipul Patel and Anirudh Deodhar and Dagnachew Birru},
howpublished = {arXiv},
year = {2026},
month = jul,
doi = {10.48550/arxiv.2607.05177},
eprint = {2607.05177},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2607.05177},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - UNPB
TI - CP-WSP: A Declarative CP-SAT Framework for Configurable Multi-Constraint Workforce Scheduling
AU - Vipul Patel
AU - Anirudh Deodhar
AU - Dagnachew Birru
PY - 2026
DA - 2026/07/06
PB - arXiv
DO - 10.48550/arxiv.2607.05177
UR - https://arxiv.org/abs/2607.05177
AB - Workforce scheduling is an NP-hard combinatorial optimization problem requiring simultaneous satisfaction of labor regulations, coverage requirements, employee preferences and operational objectives. Existing CP formulations typically model simplified instances with 6-12 constraints at shift-level granularity and critically lack explicit support for: mandatory break scheduling with midpoint placement control; acuity weighted workload equity; sub-shift temporal granularity enabling demand-driven staffing; inter-week schedule stability; and cross-midnight shift patterns common in 24-hour operations. This paper presents CP-WSP: a declarative CP-SAT framework enforcing 14 hard constraints as mathematically inviolable requirements (zero regulatory violations by construction) while optimizing 15 soft objectives through a unified weighted penalty function -- all configurable via a JSON specification with no code changes required. Key contributions include: a shift-window variable decomposition enabling mandatory break scheduling with centrality control; acuity-weighted workload equity; multi-granularity temporal resolution from 30 minutes to 2 hours; inter-week schedule stability; a grid-offset preprocessing technique for cross-midnight shifts; and a reproducible 36-configuration benchmark suite for community comparison. Evaluated on INRC-II benchmarks at both hourly and shift-level granularity and on 36 synthetic configurations.
ER -