Bachelor theses
Leveraging Transformers to Accelerate Constraint Programming for Scheduling Problems
Author
Jan Šulíček
Year
2025
Type
Bachelor thesis
Supervisor
Ing. Vilém Heinz
Reviewers
Ing. Daniel Vašata, Ph.D.
Department
Summary
In this work we use Transformer architecture to find a solution for the Flow
Shop Scheduling Problem, which we can then use to accelerate a constra-
int programming solvers search for optimal solutions. We base our model on
the architecture of TSP Transformer, which uses Transformers for solving the
Travelling Salesman Problem. We sucessfully adapt the architecture to the
Permutation Flow Shop Scheduling Problem and use the trained model for
generating warmstart for the IBM CP Optimizer solver. This accelerates the
solvers search for optimal solutions by an average of 144%, relatively to the
searches not utilizing warmstart.
We further generalize the architecture to the Nonpermutation Flow Shop
Scheduling Problem. Due to its increased complexity however, the models
training process becomes more challenging, and the model does not achieve
adequate performance. Thus, addressing the Nonpermutation Flow Shop Sche-
duling Problem requires deeper alterations to the models architecture.