where N is the number of facilities in the layout, fik the flow cost
from facility i to k, djl the distance from location j to l and Xij the
0, 1 variable for locating facility i at location j. The objective
function (1) represents the sum of the flow costs over every pair
of facilities. Eq. (2) ensures that each location contains only one
facility and Eq. (3) guarantees that each facility is placed only
in one location.