Assume Linear Model

In the standard Solver, the Assume Linear Model check box controls the choice of the linear Simplex Solver or the nonlinear GRG Solver: When it is checked, the Simplex Solver is used; otherwise the GRG Solver is used. The box is labeled "Assume Linear Model" because the Solver initially assumes that your model is made up entirely of linear functions for the objective and constraints. It solves the problem using the Simplex Solver, and then checks the solution by comparing the values for the objective and constraints calculated from the Simplex method with the values for these cells obtained when the solution values are placed in the decision variable cells and the spreadsheet is recalculated. If these values do not agree to within a close tolerance, the Solver displays the Completion Message shown below in the Solver Results dialog: