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To download a free Evaluation Version of the OptQuest Solver Engine Version 3.5, click here to sign up (free of charge) for Frontline's Private Web for Solver Users. Then click on Download, scroll to the bottom and follow the link to Download Evaluation Version of OptQuest Solver Engine.
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Frontline Systems is excited to offer the OptQuest Solver Engine Version 3.5 for Microsoft Excel 2000 and Excel 97. The OptQuest Solver is a new field-installable Solver Engine that "plugs into" the Premium Solver Platform. It employs metaheuristics such as tabu search and scatter search to solve non-smooth optimization problems of up to 5,000 variables and 1,000 constraints. It also supports integer and binary integer variables, and the new "alldifferent" constraint introduced in the Premium Solver Platform V3.5.
The Premium Solver Platform is 100% upwardly compatible with the standard Excel Solver. It replaces the standard Solver and appears when you select the usual Tools Solver... menu choice. You'll see a familiar Solver Parameters and Solver Options dialog with many new features. Your existing models can be solved with no changes, faster and more easily than before -- with any appropriate Solver engine for the Premium Solver Platform, including the OptQuest Solver Engine! And your VBA code designed to control the standard Solver will work as-is with the Premium Solver Platform.
The OptQuest Solver engine can solve non-smooth optimization problems that cannot be handled effectively by the standard Excel Solver. Even if your model uses IF, CHOOSE, LOOKUP and similar functions that cause difficulty for the standard Solver, you can obtain good solutions with the OptQuest Solver. And where the standard Solver (using the nonlinear GRG Solver engine) can find only a locally optimal solution, the OptQuest Solver is much more likely to find a globally optimal (or near-optimal) solution. The research effort leading to the OptQuest Solver Engine is described in the book Tabu Search by Fred Glover and Manuel Laguna.
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.
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.
You'll be able to solve non-smooth optimization problems as much as ten times larger than the Evolutionary Solver included with the Premium Solver Platform -- up to 5,000 variables and 1,000 constraints. (Please note: The practicality of solving large problems with the OptQuest Solver, and the time required to find "good" solutions is highly dependent on the model. The OptQuest Solver is much more likely to be effective on problems with structure that can be discovered and exploited by the methods that it employs.)
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.
The OptQuest Solver handles non-smooth problems that include general integer and binary integer variables, and variables subject to the "alldifferent" constraint, newly introduced in the Premium Solver Platform. A constraint on variables such as A1:A5 = alldifferent means that A1 through A5 are all integer variables, with values 1 through 5, all of them different at the solution. Such constraints can be used to model ordering or permutation of choices, such as the order of cities to visit in the Traveling Salesman Problem. (Note: At present, the OptQuest Solver Engine allows only one "alldifferent" constraint in a model, whereas the Premium Solver Platform allows you to define any number of (non-overlapping) "alldifferent" constraints. A model with multiple "alldifferent" constraints will elicit an error message if you try to solve it with the OptQuest Solver Engine.)
The OptQuest Solver offers several new options and tolerances to improve the speed and effectiveness of its metaheuristic methods on various types of problems. You can control the population size, the precision used to determine whether a solution is significantly better than or significantly different from previous solutions, and the frequency with which the boundaries of the solution space will be explored.
Have you ever wondered about the size of the problem you have defined, and whether it is getting close to the size limits of the Solver? With the OptQuest Solver Engine and the Premium Solver Platform, you can check the size of your problem and the corresponding size limits in the Options dialog at any time.
The OptQuest Solver can produce a Population Report in addition to the standard Answer Report. Where the Answer Report gives you detailed information about the single "best solution" returned by the Solver, the Population Report gives you summary information about the entire population of candidate solutions maintained by the Solver at the end of the solution process. The Population Report can give you insight into the performance of the OptQuest Solver as well as the characteristics of your model, and help you decide whether additional runs of the Solver are likely to yield even better solutions.
If you've ever found it difficult to enter your decision variable cells in the Solver because they are scattered around your worksheet, the OptQuest Solver Engine and the Premium Solver Platform are for you! They offer a variable cell list box entry alternative that allows you to enter an unlimited number of cell ranges.
If you're tired of selecting Tools Solver... from the menu bar over and over as you solve various problems, you'll appreciate the "Return to Solver Parameters" check box in the Solver Results dialog, which lets you "stay within the Solver dialogs" until you need to work directly on your spreadsheet.
And if your problem includes integer constraints, you can obtain a quick solution of the "relaxation" (temporarily ignoring the integer constraints) without having to delete these constraints and then re-enter them later.
The OptQuest Solver Engine V3.5 is priced at $995 for a single-user license. It includes 90 days of knowledgeable technical support and automatic upgrades to new versions. You can order today with a 30-day money-back guarantee. Discounted prices are available for qualified academic users -- contact Frontline Systems for more information.
CONTACT US TODAY: Send us email, call us at (775) 831-0300, or send a fax to (775) 831-0314.
