Rockwell Automation Arena OptQuest Users Guide - Manual (Page 46)

A RENA O PT Q UEST U SER ’ S G UIDE
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However, several factors affect OptQuest’s performance, and the importance of these
factors varies from one situation to another. This chapter reviews these factors and offers
tips and suggestions on how to achieve maximum performance.
Factors that affect search performance
Any heuristic method for solving problems cannot guarantee to find the optimal solution.
It might only find a solution that is very close to the optimal solution, often called the best
solution. This is why maximizing performance is so important.
The following is a list of the relevant factors that directly affect the search performance:
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Number of controls
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Initial values
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Bounds and constraints
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Complexity of the objective
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Feasibility
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Number of replications and simulations
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Simulation accuracy
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Simulation speed
Number of controls
The number of controls greatly affects OptQuest’s performance. OptQuest has no physical
limit on the number of controls you can use in any given problem. However, the perfor-
mance might deteriorate if you use more than 100 controls.
Also, as the number of controls increases, you need more simulations to find high-quality
solutions. General guidelines for the minimum number of simulations required for a given
number of controls in a problem are:
For very large numbers of controls, you might try this procedure:
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Increase the number of simulations by lowering the number of replications per
simulation, at least initially.
Controls Minimum number of simulations
Fewer than 10 100
Between 10 and 20 500
Between 20 and 50 2000
Between 50 and 100 5000