Assembly line balancing with parallel workstations

ABSTRACT

The simple assembly line balancing problem (SALBP) considers work division among different workstations of a serially arranged assembly process to maximise its efficiency under workload (cumulative) and technological (precedence) constraints. In this work, we consider a variant of the SALBP which allows parallel workstations. To study the effect of parallel stations, we propose a new problem (the parallel station assembly line balancing problem or PSALBP) in which the objective is to minimise the number of parallel stations required to obtain the maximum theoretical efficiency of the assembly process. We study the complexity of the problem and identify a polynomially solvable case. This result is then used as a building block for the development of a heuristic solution procedure. Finally, we carry out a computational experiment to identify the characteristics of assembly lines that may benefit from station paralleling and to evaluate the performance of the proposed heuristic.

Keywords:

• Line balancing
• parallel stations
• dynamic programming
• hybrid metaheuristic
• matheuristic

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research has been partially funded by the National Commission for Scientific and Technological Research CONICYT, Chile, through research grant N. 1191624 ‘Assembly Line Balancing for Industry 4.0’. E. Álvarez-Miranda also acknowledges the support of the National Commission for Scientific and Technological Research CONICYT, Chile, through funding from FONDECYT N. 1180670, FONDECYT N. 1191624 and through the Complex Engineering Systems Institute PIA/BASAL AFB180003.

Notes on contributors

Eduardo Álvarez-Miranda

Eduardo Álvarez-Miranda is Associate Professor of Industrial Engineering, at the Faculty of Engineering, Universidad de Talca in Chile. He is also a researcher of the Complex Systems Engineering Institute, Chile. He received his PhD in Operations Research in 2014 from the University of Bologna, Italy. His research interests are focused on the development and application of mathematical optimisation techniques for problems from different application contexts.

Sebastián Chace

Sebastián Chace is an Operations Research M.Sc. candidate and Industrial Engineering B.Sc. at Universidad Adolfo Ibáñez. He currently works at Ernst&Young as Analytics consultant.

Jordi Pereira

Jordi Pereira is Associate Professor at the Faculty of Engineering and Science, Universidad Adolfo Ibáñez in Chile. He received his PhD in Engineering in 2004 from the Universitat Politècnica de Catalunya, Spain. His research considers the development of solution procedures for combinatorial optimisation problems in different application areas with special interest in assembly line balancing problems.