How To Use Sequential Objectives

Sequential Objectives allow for you to set multiple tiers of objectives for the optimization solve to consider, where each tier of objectives can be relaxed by a defined percentage when solving for the next tier.

Here is a basic example of how Sequential Objectives can be used.

Problem Definition

100 units of demand for P1 at CZ.

Available pathways for flow are as follows:

• MFG > DC1 > CZ which has a cost of $5/unit with a travel time of 10 DAY
• MFG > DC2 > CZ which has a cost of $25/unit with a travel time of 1 DAY

Find a solution that will first minimize total costs, but then will work to minimize the total amount of travel time in the solution while only relaxing the Total Cost solution by 20%.

Baseline Solution

When just solving with the standard objective of Profit Maximization, the cheapest path will be utilized. All flows will come from MFG > DC1 > CZ and the total cost will be $500.

Sequential Objective Solution

We’ve built the Sequential Objectives so that we will first optimize over the Total Supply Chain Cost as Priority 1. We have also set the Tolerance to be 20 which will allow for a 20% relaxation in the solution to solve for the secondary objective – Total Weighted Flow Time.

We’ll now see that the more expensive pathway of MFG > DC2 > CZ is used as it requires less travel time. Because the initial cost was $500, we will send as many units as possible through DC2 up until the total cost reaches $600 – a 20% deviation from the initial cost. This results is 5 units flowing via DC2, while 95 units remain through DC1 for a total cost of $600.

This example model can be found in the Resource Library listed under the name of Sequential Objectives Demo.