More New Features in Premium Solver Platform
Click on the Premium Solver Platform features of interest to you. These features are also supported by several field-installable Solver engines for the Premium Solver Platform.
When the Solver reports that it cannot find a "feasible solution" (one which satisfies all of the constraints), this often means that you've made a mistake in defining some constraint, for example by choosing <= when you meant >=. But if you have hundreds of constraints, it can be difficult to pinpoint the source of the problem. The Premium Solver Platform's new Feasibility Report can help! This report eliminates constraints which do not contribute to the infeasibility, and highlights a minimal set of constraints which are conflicting.
With the Feasibility Report, you can quickly locate the error or condition that makes the problem infeasible. (Click on the worksheet below to see it full size.)
If you've ever received the message "The conditions for Assume Linear Model are not satisfied," but you couldn't find the problem in your model, the Premium Solver Platform is for you! It features a new Linearity Report, which shows you whether the objective and each constraint is a linear or nonlinear function of the variables. It also summarizes which variables occur linearly, and which occur nonlinearly in the objective and constraints.
With this report, you can pinpoint and, if desired, eliminate nonlinear formulas in your models, thereby gaining the extra speed and reliability available with all-linear Solver models. (Click on the worksheet below to see it full size.)
In the Premium Solver Platform, all five reports (Answer, Sensitivity, Limits, Linearity and Feasibility) can be optionally, automatically outlined. The outlined groups of variables and constraints correspond directly to the cell ranges you entered in the Solver Parameters dialog. If you have large numbers of variables and constraints, outlining can make it much easier for you to find and display the information you need in the Solver reports.
If you need fine-grained control, the Premium Solver Platform lets you adjust the most critical tolerances in both the linear Simplex and nonlinear GRG solvers. Similarly, field-installable Solver engines let you adjust the tolerances that are critical for their algorithms. And you can speed up the solution of problems with integer constraints by supplying an "integer cutoff" value -- often known from a previous run.
Have you ever wondered about the size of the problem you have defined, and whether it is getting close to the size limits supported by your Solver engine? In the Premium Solver Platform, you can check the size of your problem and the corresponding size limits at any time.
Have you ever wondered just how long "Setting Up Problem..." would take? If so, you'll appreciate the new progress reporting in the Premium Solver Platform, which shows an estimated "nn% Done" for both problem setup and generation of the Limits and Feasibility Reports, which can be time-consuming for larger models.
If you've found it difficult to enter your decision variable cells in the Solver because they are scattered around your worksheet, the Premium Solver Platform is for you! It offers 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.
If online Help in Microsoft Excel has left you with more questions than answers, you'll appreciate the comprehensive User Guide that comes with the Premium Solver Platform. It provides complete information on Solver options and reports, the various messages which the Solver can return, how to diagnose problems, and how to control the Solver from Visual Basic Application Edition (VBA).