The double row layout problem with safety consideration: a two-stage variable neighborhood search approach

The double row layout problem (DRLP) concerns on arranging a set of machines with various size on the two parallel rows with the aim to minimize the handling cost of material flow between machines. In some industrial applications, the layout planning requires the decision-makers to consider the safety factor, enforcing them to comply with a minimum distance between machines. Therefore, this study considers the inclusion of a safety factor in the DRLP, and a two-stage variable neighborhood search-sine cosine algorithm is proposed. In the first stage, the improved variable neighborhood search (IVNS) is developed for determining the placement of the machines in both rows. Then, in the second stage, a sine-cosine algorithm (SCA) is presented for adjusting the exact position of machines in the shorter row. The effectiveness and efficiency of the proposed algorithm are demonstrated by extensive computational test with various level of complexity.