Optimization with OptQuest®

In today’s highly competitive global environment, people are faced with many difficult decisions, such as allocating financial resources, building facilities, managing inventories, determining product mix strategies, and more. Modeling a decision problem in SIMPROCESS discovers what performance measures can be expected using a certain strategy.

A strategy can be defined as a certain set of values for the model parameters. Other words for strategy include scenario and solution. Note that “solution” refers to the model parameter values (inputs to the simulation) not the resulting values of the performance measures.

Suppose the goal was to find the best strategy. Model parameter values for a strategy being considered would have to be entered into SIMPROCESS and the results analyzed. Then this process would have to be repeated for every strategy under consideration. The Experiment Manager automates running models with various values for model parameters, but often it is not clear how to adjust the model parameters from one simulation to the next. This type of search can be tedious and, in problems with thousands or millions of potential alternatives, impractical.

OptQuest® enhances SIMPROCESS by automating the search for an optimal strategy. OptQuest® for SIMPROCESS is an optimization tool created by OptTek. Since OptQuest® is an optimization tool, it attempts to minimize or maximize the value of a performance measure based on limits (constraints, upper bounds, and lower bounds). OptQuest® automatically runs SIMPROCESS models varying the values for the model parameters searching for optimum results within the specified limits.

When the optimization runs:

  • OptQuest® feeds a potential solution into SIMPROCESS model by setting the decision variable (model parameter) values.
  • SIMPROCESS runs one simulation (which may include multiple replications) to evaluate the solution.
  • OptQuest® takes the resulting response values from SIMPROCESS.
  • OptQuest® analyzes the results of the simulation and uses its intelligent search procedures to generate a new potential solution, which it then sends to SIMPROCESS.

OptQuest® repeats this process. Its ultimate goal is to find the solution that optimizes (maximizes or minimizes) the value of the model’s objective.

See Chapter 4 of Part E of the SIMPROCESS User’s Manual for more information

Defining Optimization