Balancing parallel assembly lines with disabled workers

TL;DR

This paper addresses the complex problem of balancing parallel assembly lines in sheltered workshops with disabled workers, proposing a mixed-integer model and heuristic to optimize worker assignment and line layout.

Contribution

It introduces a novel formulation and heuristic for the parallel assembly line balancing problem specific to disabled workers, enhancing existing methods.

Findings

Allowing alternative line layouts improves efficiency.

The proposed methods outperform existing approaches.

Large instances demonstrate practical applicability.

Abstract

We study an assembly line balancing problem that occurs in sheltered worker centers for the disabled, where workers with very different characteristics are present. We are interested in the situation in which parallel assembly lines are allowed and name the resulting problem as parallel assembly line worker assignment and balancing problem. We present a linear mixed-integer formulation and a four-stage heuristic algorithm. Computational results with a large set of instances recently proposed in the literature show the advantages of allowing alternative line layouts.