The World's Most Powerful Solver for Microsoft Excel

What'sBest! offers unmatched solution speed, capacity and reliability. The internal linear, nonlinear and integer solvers utilize state-of-the-art techniques, and our dedication to ongoing development will ensure their continued superiority.

Speed

When it comes to speed, What'sBest! outperforms stand alone solvers, much less any competing spreadsheet solver. Its commercial quality Linear Programming solver combines with superior Integer Programming technology set a new standard in optimization speed.

Capacity

While competing spreadsheet solvers boast of "industrial strength" versions handling LP models of up to 2,000 variables, the largest version of What'sBest! has no capacity limit. What'sBest! users routinely solve models of well over 100,000 variables.

Reliability

Day in and day out, thousands of companies around the world rely on What'sBest! to provide critical solutions to their toughest optimization problems. What'sBest! is able to solve complex and numerically difficult problems that competing products simply cannot.

Linear Solvers

What'sBest! is available with three state of the art solvers for linear models.

Primal and Dual Simplex Solvers
The base version includes the Primal and Dual Simplex solvers, which incorporate numerous enhancements for maximum speed and robustness. Pricing options, for instance, include partial pricing and Devex. The solver dynamically chooses the best pricing option based upon problem characteristics.

Barrier Solver

The optional Barrier solver provides an alternative means of solving linear models. The Barrier option utilizes a barrier or interior point method to solve linear models. Unlike the Simplex solvers that move along the exterior of the feasible region, the Barrier solver moves through the interior space to find the optimum. Depending upon the size and structure of a particular model, the Barrier solver may be significantly faster than the Simplex solvers and can provide exceptional speed on large linear models -- particularly on sparse models with more than 5,000 constraints or highly degenerate models.

Preprocessing routines are available with all three What'sBest! linear solvers. Scaling procedures can improve speed and robustness on numerically difficult models. Model reduction techniques can often make models solve faster by analyzing the original formulation and mathematically condensing it into a smaller problem.

Nonlinear Solver

For nonlinear programming models, the primary underlying technique used by What'sBest's optional nonlinear solver is based upon a Generalized Reduction Gradient (GRG) algorithm. The nonlinear solver takes advantage of sparsity for improved speed and more efficient memory usage. It also offers a variety of algorithmic options including a Crash procedure, a Steepest Edge/Steepest Decent option, and Sequential Linear Programming procedures. What'sBest! will automatically select the solution approach that appears best suited to the specific model at hand. The solution approach is dynamically adjusted during the solution process based upon the model's behavior.

Integer Solver

For models with general and binary integer restrictions, What'sBest! includes an integer solver that works in conjunction with the linear and nonlinear solvers. For linear models, the integer solver does extensive preprocessing and adds constraint "cuts" of several different varieties to greatly improve solution times on large classes of integer models.

Intelligent Integration

What'sBest! handles the details of the solution process, so you can focus on modeling. When the Solve command is initiated, What'sBest! analyzes the problem and, when possible, reduces the problem and even substitutes out variables. With What'sBest!, you never have to specify whether to use the linear or nonlinear solver. Based upon the model's structure, What'sBest! automatically selects the appropriate solver and intelligently adjusts internal parameters.

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