Rockwell Automation Arena OptQuest Users Guide - Manual (Page 45)

41
5
5
• T
ips and Sug
gest
io
ns
Optimization Tips and Suggestions
This chapter describes the different factors that affect how OptQuest searches for optimal
solutions. Understanding how these factors affect the optimization helps you control the
speed and accuracy of the search.
Overview
There are many factors that influence the performance, defined as the ability to find high-
quality solutions as fast as possible. For example, consider two optimization methods, A
and B, applied to a profit-maximization problem. When you evaluate the performance of
each method, you must look at which method:
„
Finds a solution with a larger profit.
„
Jumps to the range of high-quality solutions faster.
Below is the performance graph for the two hypothetical methods.
This graph shows that although both methods find solutions with a similar expected profit
after 10 minutes of searching, Method A jumps to the range of high-quality solutions
faster than B. For the criteria listed above, Method A performs better than Method B.
While using OptQuest, you will obtain performance profiles similar to Method A.
OptQuest’s search methodology is very aggressive and attempts immediately to find high-
quality solutions, causing large improvements (with respect to the initial solution) early in
the search. This is critical when OptQuest can perform only a limited number of simula-
tions within the available time frame.
0
20
40
60
80
100
1 2 3 4 5 6 7 8 9 10
Tim e (Minutes)
Expected Profit
Method A
Method B