Home / Monte Carlo / Model Building / Create Monte Carlo Design Sheet / Create Design Sheet How-To

Create Design Sheet How-To¶

This walkthrough writes a design sheet: a worksheet laid out as a model, with every row already marked, so you fill in a table rather than marking cells one at a time.

Steps¶

QXL Monte Carlo New > Design > Create/Modify Design Sheet > Create Monte Carlo Design Sheet.
Ask for 2 inputs and 1 output.
Finish. A new sheet appears, already marked.

What you get¶

A block per input and a block per output, each with its parameters laid out in labelled cells, and the sheet is protected so the structure cannot be edited away by accident. The cells you fill are the ones left unprotected.

Every row is already marked, which is the point of the sheet: you do not run Mark Input on it.

Fill it in¶

Give the first input a Normal distribution with mean 10 and standard deviation 0.2, the second a Normal with mean 4 and standard deviation 0.1, and write the output's equation against the two input cells. Give the output a lower limit of 23 and an upper limit of 25.

Then run it. Run Model treats this sheet exactly as it treats a workbook you marked by hand.

The same model on a plain sheet¶

A design sheet is one of two ways to reach the same model, and the comparison is worth making once. The block below is that model written out as an ordinary worksheet, which you mark by hand with Mark Input and Mark Output.

This walkthrough uses a small model you can build in a minute: two inputs, one output, and a specification band that half the output sits outside of.

Press Copy for Excel, then paste the table into a blank worksheet.

Model	Value
Wall thickness	10
Bore	4

Outside width	`=B2*2+B3`

Click cell A1 in a blank worksheet and press Ctrl+V. The two headings land in row 1, the labels in column A, and the model in column B: B2 holds the wall thickness, B3 the bore, and B5 the formula that reads them both. The empty row is deliberate, so the output lands in B5 and not B4, which is what every Monte Carlo walkthrough calls it.

Mark B2 and B3 as inputs, giving each a Normal distribution: B2 mean 10 standard deviation 0.2, B3 mean 4 standard deviation 0.1. Mark B5 as an output with a lower limit of 23 and an upper limit of 25.

The two sheets run identically. Nothing about the simulation can tell them apart: the design sheet is the route to use when the model is being built from nothing, and marking a plain sheet is the route to use when the formulas are already there.

There is nothing to paste into the design sheet itself, and that is deliberate rather than an omission: the design sheet's cell layout is written by the dialog and depends on how many inputs and outputs you asked for, so the cells to fill are found by their labels rather than by address.

Things to try next¶

Add an input afterwards with Modify Monte Carlo Design Sheet rather than rebuilding the sheet.
Run Validate Model before a long run.
Run it both ways and compare, which is what the section above sets up.