A new area linearization method for Unequal area facility layout problem

This paper propose an improved MIP formulation to reach the objective of Unequal area facility layout problems (FLP) that is to minimize the total material handling cost. Facility layout problem is defined as locating departments in facility with a given dimension, and the departments can't overlap. The FLP can be formulated as a mixed-integer programming (MIP). In past researches, many researchers use polyhedral outer-approximation to improved MIP formulation but in this paper the model uses an inner-approximation method to meet the constraints of FLP. The important change will make the area of each departments in the problem can bigger or equal to the given constraints and can meet the needs of the department the function of the area. Test results show the area of departments is all greater or equal to the given departments size rather than less to required area.