As mentioned in the previous paragraphs, over time the mix of parts, the volume of production for each part and the routing for each part in the system is generally subject to change. If everything remains constant for long period of time, a dedicated set of facilities would be more appropriate but where this is not the case, there is a need to focus on a re-layout issue. The objective function in a DLP is generally defined as the minimisation of flow costs plus rearrangement cost for a series of static layout problems [3,5,6]. In a dynamic layout problem, rearrangement costs are added whenever an area contains different departments in consecutive time periods.