Excel Solver: Min Std Dev and changing variable cells by a defined increments ?

I do not fully understand your solver model and spreadsheet. One observation that seems to be at least part of the problem. Two of your constraints are telling Solver to make D4:K4 between 10 and 70 (D11:K12). I notice that K10=7, and I cannot find a combination of values that will change this value. I am guessing that Solver cannot, either. Because it cannot force K10 to be between K11 and K12, it gives up. I also note that, by changing K11 to be 5 (or some other value less than 7, since 7 seems to be the value this cell wants to be), Solver can run and find a solution.

I'm not sure what your final solution should be, but I would suggest that you need to examine your constraints (either as defined in Solver or as computed in the spreadsheet) more carefully to make sure they accurately reflect the desired Solver model.

On edit: I also note that just about any value above 20340 (I even tried 40000) in D4:K4 seems to satisfy the specified criteria, so the overall model may not be very specific. If it is adequate, then great, but you may find that you sometimes get very different results for the same set of conditions.

As it stands now, there is nothing in D5:K5 (my mistake on the row #), which means the stdev() function returns an error, which Solver cannot work with. You need to enter something into D5:K5 as a starting value. When I tried it, that gave Solver something to work with (larger than expected, say start at 40000), and it was able to find a solution.

Another observation: I can enter an insanely large number into production and never get more than about 56 DOH, If I extend the OFFSET() function so that it is possible to get more than 70 DOH, I quickly (manually) find that any value for production between 20500 and 43500 appears to satisfy the constraints given. For a different approach to the analysis, you might determine the minimum production that meets the criteria and the maximum production, then report that anything within that range meets the criteria.

Another observation. The minimum in the stdev() will always be when all values in row 5 are equal. Unless there is something else in your real spreadsheet that changes that conclusion, this seems like almost a trivial solution. I am not in a position to understand how this fits into your strategizing, so I'm not sure I can suggest a better model. It seems to me that, minimizing the stdev() is not the most interesting variable for an objective function in this case.