Solver - decimal places

[Sean Thomas]

Hi
Im new to using solver

I have 3 values that require changing but would prefer to be kept to 2 decimal places.
They are formats of
£00.00
0.0%
0.0%

however what ever restraints I place they will return up to 13 decimal places.
This provides me with the wrong answer
is there anyway I can limit the values to be changed to the above formats

[José Augusto]

Hi

Have you tried ROUND ?
Attach a sample workbook (not a picture or pasted copy). Make sure there is just enough data to demonstrate your need. Include a BEFORE sheet and an AFTER sheet in the workbook if needed to show the process you're trying to complete or automate. Make sure your desired results are shown, mock them up manually if necessary.

Remember to desensitize the data.

Click on GO ADVANCED and then scroll down to Manage Attachments to open the upload window.

[Sean Thomas]

I cant use round.
Its not a case of just rounding the numbers up
Solver changes the values in cells J5:J7 and these are the figures I want to control via solver.
I have some values that are certain.
Labour hours
Parts (retail cost)
Paint (retail cost)
other (retail cost)

I have a target value of £1350 of which I am trying to get solver to achieve this figure.
If I set solver to get the 3 variables to change to calculate the exact amount it will return results with say 11 decimal places.
If I was to replace these with results rounded up to 2 decimal places then it would calculate a different value

Solver only seems to allow you to use integers or it will use any decimal value but doesn't seem to allow the constraints to be to 2 decimal places.

[José Augusto]

Hi

In solver use LP Simplex

See the file

[Sean Thomas]

That isn't calculating if I try changing the target to 1400

[MrShorty]

IMO, Solver is not going to like trying to have "number of decimal places" as part of its model. Here's how I would do this:

1) Run Solver like you currently have it to get the "exact" solution to the problem.
2) After Solver comes to the exact solution, round the values up/down to the desired precision so that K9 will be larger than K11. You can do this manually, or have a second copy of this block of cells that performs the calculation with the rounded values. It depends on how this fits into your overall project and how automated it must be.

Looking at Jose's file and my sample runs, it appears that there are multiple possible solutions for a given problem. One of my runs gave me 25.0, .147, .890 to get something just larger than 1350. Another run gave me 25.1, .112, .834 to get 1350. I note that Jose's run gave him 25.0, .010, .693 for 1350. If you are not concerned by this, then don't worry about it.

[José Augusto]

Hi

See this model Evolucionary.

The formulas in K6:K8 uses ROUND as you need

[Sean Thomas]

Thanks Mr Shorty
I pretty much came up with the same solution in the end