Skip to content

Excel Solver for Linear Programming

Definition

Excel Solver for linear programming represents the LP's decision variables in changing cells, its objective in a formula cell, and its constraints through formulas and bounds. The course uses the Simplex LP solving method for continuous linear models.

Interpretation

Solver is a numerical tool: it solves exactly the model typed into the spreadsheet, nothing more and nothing less. The spreadsheet must therefore represent the same objective, coefficients, constraints and variable domains as the mathematical model.

Each part of the linear program formulation has a place in the sheet: changing cells for the decision variables, an objective cell with a formula that adds up coefficient times variable, and a formula cell for the left-hand side of each constraint, compared in the Solver dialog with its right-hand side. The Simplex LP method requires these formulas to be linear in the changing cells.

Restrictions that are obvious in words must still be entered: nonnegativity, and integer or binary restrictions as constraints of type int or bin. Solver cannot supply a restriction that was omitted, and a typing error in one coefficient changes the problem without any warning. A message that no feasible solution was found corresponds to an infeasible linear program, and a message that the objective cell values do not converge to an unbounded one.

Key Results

  • Use the specified maximization or minimization direction.
  • Integer and binary restrictions must be added explicitly when solving an integer model.
  • A reported solution should be checked against the original constraints.
  • What matters is the model entered and the reported outcome, not the layout of the Solver dialog in a particular Excel version.

Examples

  • Week 2 practice 1(a) has optimum (14/3,4/3)(14/3,4/3) and value 32/332/3.
  • Practice 1(b) has optimum (4,9,6)(4,9,6) and value 19.

Prerequisites

Sources

Aliases: Excel Solver, Solver add-in Keywords: Solver

Last updated: 20 October 2026 03:02