ModelRisk Optimizer: optimisation under uncertainty in Excel

Excel’s Solver optimises a single-point model. When the inputs are uncertain, the plan that looks best on the average case can be a poor plan across the range of outcomes: the portfolio that maximises expected NPV may carry a 30% chance of a loss your board would never accept. Optimising on the simulated output lets you define “best” in risk terms (the highest median NPV with at most a 10% chance of a loss, say) and get an answer that respects it. (Illustrative numbers, not a customer result.)

• Portfolio selection: which projects to fund within a capital budget, maximising expected value while keeping the chance of missing a return target below a limit.
• Contingency and reserve setting: the smallest reserve that meets a target confidence level across several cost lines (see how to calculate cost contingency).
• Inventory and capacity: order quantities or capacity levels that balance stock-out risk against holding cost.
• Capital and limit allocation in insurance and finance: allocating across lines under a tail-risk constraint.

The same release adds the Turbo engine: ModelRisk analyses the workbook once, compiles only the cells that change between iterations and runs them on every processor core. Across 89 models from our internal test library, the simulation phase ran a median of about 200 times faster than ModelRisk’s classic engine, and two in three of them more than 100 times faster (same workbook, 1,000 iterations, excluding the one-time model analysis). The gain depends on the model. Optimisation runs many simulations back to back, so this is where the speed matters most. Turbo is included in the standard licence too.

Yes. ModelRisk converts @RISK and Crystal Ball models free of charge, and the converter now brings RISKOptimizer models across as well. Converted models remain ordinary Excel workbooks that colleagues can open and audit. ModelRisk costs at most €1,550 per user per year, about half the price of @RISK Professional (€2,900 per year on Lumivero’s web shop, retrieved October 2026), and the optimiser is included in that price. Step-by-step guides: switching from @RISK and ModelRisk vs Crystal Ball.

Start the free 15-day ModelRisk trial, which is fully functional. If you have an optimisation model you would like to move across, send it to us and we will help you convert it. Release details are in the ModelRisk release notes.

Start the free 15-day trial