Unidirectional Loop Layout Problem with Balanced Flow

The unidirectional loop is an economical and flexible materials handling system transporting materials around a loop network in one direction only. There are n candidate locations around the loop to allocate n machines. This configuration is easily adaptable to changes in product mix and routing requirements. The challenge here is to find an assignment for machines to available sites to minimize the handling cost. If the material flow is conserved at each workstation, that is, if total inflow is equal to total outflow then such a loop is called as a balanced loop. This work addresses the unidirectional loop layout design problem with balanced flow. The problem is known to be NP-complete, and thus heuristic methods and artificial intelligence techniques are appropriate to solve such difficult problems in reasonable time. A hybrid Genetic Algorithm (GA) based on a move heuristic is developed to solve the problem. The performance of the GA is tested by using well known data sets from literature and considerable improvements are obtained.