Abstract: Facility Layout Problem (FLP) has significant impact on manufacturing efficiency. It involves determining the optimal placement of different types of facilities within the boundaries of the workshop. FLP can be categorized into Static Facility Layout Problem (SFLP) and Dynamic Facility Layout Problem (DFLP). DFLP takes possible changes into account in the product demands over multiple periods. The facilities may need be dynamically placed several times to accommodate various demands accordingly. This work studies the DFLP under uncertain product demands. First, to solve the FLP caused by uncertainty and dynamics of material requirements between facilities, a method of dynamic facility layout combined with fuzzy-random theory is proposed considering the deficiency of the description of uncertain demands. Then, the main factors causing uncertain demands are analyzed and the uncertain demand are presented by fuzzy random variables. To minimize the material handling cost, rearrangement cost and total distances between various departments and maximize the area utilization ratio, a multi-objective dynamic layout model with unequal-area departments is established under fuzzy random environment. Finally, combining with system layout planning, the optimization method of the position-based colonial competitive algorithm is proposed to obtain feasible optimal solutions for the proposed problem. The rationality of the established model is validated by comparing practical model among the determined demands, random demands and fuzzy random demands. The effectiveness of the algorithm is demonstrated by computational results of the practical problems.

Key words: mechanical engineering, dynamic facility layout, uncertain demands, unequal-area departments, position-based colonial competitive algorithm