Production lines, designed in a serial manner, have attracted the attention of researchers for many years. Line efficiency, throughput time and workload balancing are the main concerns regarding assembly lines, due to the high volume production. Recently, specific assembly line configurations, such as two-sided and parallel lines, have been addressed by researchers within the operational levels of production. Parallel two-sided assembly lines, rather a new research area, allocate more flexible workers and reduce throughput time by incorporating the advantages of two-sided and parallel assembly lines. Since parallel two-sided assembly lines are utilized to produce large-scale products, such as automobiles, trucks, and buses in industry; they also require a significant worker movement between parallel lines because of the unavoidable walking distances between lines. In this respect, different from the existing literature, walking distances have been included in parallel two-sided assembly line balancing problem. The main purpose of this paper is to introduce parallel two-sided assembly line balancing problem with walking times and to propose the implementation of Bees Algorithm and Artificial Bee Colony algorithm due to the NP-hardness of the problem. An extensive computational study is also carried out and the comparative results are presented. 
Bee algorithms for parallel two-sided assembly line balancing problem with walking times