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| You can solve simulation
optimization problems with the combination of the Premium
Solver and Risk Solver.
By itself, Risk Solver (which is licensed as a separate
product) gives you lightning-fast, Interactive Simulation
in Microsoft Excel – new simulation results each time you change
the spreadsheet, up to 100 times faster than using Excel alone.
With Risk Solver, your models can include
uncertain variables whose values are defined by
probability distributions. You can use the cells
containing these uncertain variables in any formula in your model.
Risk Solver will perform a Monte Carlo simulation
with thousands of trials, where a different value is sampled for
each uncertain variable on each trial, and your model is
recalculated with these values.
Statistics across all the trials are accumulated for any
formula cell you designate. You can access these statistics in
regular Excel formulas. And in the Premium Solver, you can use
these formulas in the objective and constraints of
your optimization model. When you click Solve, the Premium
Solver performs a Monte Carlo simulation through Risk
Solver on each Trial Solution of the optimization.
Doing this is usually an order of magnitude faster than in
competitive products for simulation optimization. |
Click on the PSI Simulation Options
dialog to see it full size. |
Defining a Simulation Optimization Model
Creating a simulation optimization model using the
Premium Solver and Risk Solver is straightforward.
You follow these steps:
- Define decision variable cells (such as A1),
using either the Solver Parameters dialog or the PsiVar()
function. These are factors that are under your control – you
(or the Solver) will decide what values they should have.
- Define uncertain variable cells (such as A2),
that contain formulas calling the PSI Distribution functions
supplied by Risk Solver – for example PsiUniform() and
PsiNormal(). These are factors that are not under your
control.
- Build your model, using cell formulas that
may depend on the decision variables, uncertain variables, or
both.
- Each cell (such as B1) containing a formula
that depends on uncertain variables (say =A1+2*A2) represents
thousands of trial values, generated during each Monte Carlo
simulation by sampling different values for A2 and computing
=A1+2*A2.
- In other cells (such as C1), define the
summary statistics you want, using functions such as PsiMean(B1)
or PsiStdDev(B1). You may use formulas to compute further values
based on these summary statistics.
- Define your objective and constraints for
optimization. These may be cell formulas that depend only on the
decision variables, depend on the uncertain variables through
PSI Statistics functions, or depend on both.
Solving a Simulation Optimization Model
Solving a simulation optimization model using the
Premium Solver and Risk Solver is also
straightforward. Follow these steps:
- Activate Interactive Simulation by clicking
the light bulb button on the Risk Solver Ribbon or toolbar.
- Select Tools Premium Solver to display the
Solver Parameters dialog, and click the Solve button.
Back to Risk Solver Product Overview
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Product Overview
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