ISEN 601 Location Logistics Dr. Gary M. Gaukler Fall 2011

2-Center Problem Alternative formulation (P1): Note:

2-Center Problem Looks almost like a covering problem! Consider the covering problem C(z): Note that for the 2-center case, the minimal objective function value of C(z) must be <=2

2-Center Problem Equivalence of C(z) and P1:

2-Center Problem Hence:

2-Center Problem Example:

2-Center Problem Example:

2-Center Problem Example:

2-Center Problem Example:

2-Center Problem Example:

n-Center Problem General approach:

n-Center Problem Algorithm:

n-Center Problem Algorithm:

Location on General Networks Example:

Median Problem on GNs Recall: node optimality for median problems

Node Optimality on GNs Let’s look at a 1-median problem:

Node Optimality on GNs Distances for the sample network:

Node Optimality on GNs

Solving the 1-median Problem