Intelligent, Population-Based Search
Where classical optimization methods keep track of
a single "best solution" found so far, the OptQuest Solver
maintains a population of candidate solutions. Any member of
the population can give rise to a new, better solution, possibly far
away from the "best solution" found so far. Because
of this, the OptQuest Solver is unlikely to become
"trapped" in the region of the locally optimal solution.
Tabu Search and Scatter Search
The OptQuest Solver uses metaheuristics
such as tabu search and scatter search, with
"memory" and "aging" of members of the
population, to guide the generation of new trial solutions. Compared
to a genetic or evolutionary algorithm, like the one used in the
Evolutionary Solver in the Premium Solver Platform, the OptQuest
Solver makes greater use of strategic choices and less use of
randomization. For example, the OptQuest Solver generates new points
from linear combinations of existing points in the
population, designed to lie both inside and outside the convex
region spanned by the existing points -- where an evolutionary
algorithm typically generates new points from random or semi-random
combinations of existing points.
Automatic Handling of Linear Constraints
While it can handle any type of Excel function --
linear, nonlinear, or non-smooth -- the OptQuest Solver will automatically
recognize and exploit any linear constraints in the model. It
uses a variant of the Simplex method to "solve for" these
constraints, thereby effectively reducing the dimensionality of the
space to be explored. Models that include a significant number of
linear constraints in addition to some non-smooth constraints are
especially well-suited for the OptQuest Solver.
Highly Effective Handling of Integer Constraints
The OptQuest Solver is especially
effective at solving non-smooth problems with integer constraints
(including "alldifferent" constraints). It often
outperforms all other known solution methods on these problems,
including genetic and evolutionary algorithms -- even the Premium
Solver Platform's hybrid Evolutionary Solver.
Population Report
