Solver with multiple variables (56)

Looks like a stock-cutting issue.
I don't quite understand your meaning of "days".
Is there any connection between days and molds?
Why do you put days as decision variables?

Hey,

Yes there is a connection, if you choose to use for example "mold 1" to work for "1 day" (A25), then you can see that in "mold 1 table" (A2:D9) you will get the 40+30 monthly manufactured product. Because "mold 1" is "75-75-75-75-100-100-100" in size, total of 600mm. We have 4 lines of "75 mm" (C4) and 3 lines of "100 mm" (C5) sized final product, we can "produce" 10 molds per day (L14) so we have 10*4*1=40 (D4) where 10 is molds per day, 4 is lines per mold, 1 is 1 day. If we will work for 2 days, with the same "mold 1" it will be 10*4*2=80 and so on.
After that, this amount of final products (by sizes) are summed up in B14:B19, (every 4-th row, D-H-L-P-T....) they are taking part to build constraints also and in final "Total profit" cell, which we want to maximize.
So we want to know which "mold" we should work with and for how many days to get the best result with given constraints. Maybe we can choose 5 different molds and work for 6 days per mold in total of 30 days, or we can choose 4 different molds and work for 10-5-4-11 days.
"To choose a mold" means you work it for 1 day at least, if you don't want to choose/use a mold you can write 0, in "days" row (25).

Hope I explained that understandably?

I really hope to find some help here

Hey,

Thanks for your response. I have seen your file, yes I want to maximize profit with given min & max requirements.
Your solution seems perfect, model is great, you had some "mechanical errors" in data, you have entered data (min, max, profit) for 50 mm in 250 mm mold cells and etc. But it's nothing. I have corrected all small issues and now waiting for solver to solve the problem, 5 mins have passed

I will update you for the outcome, hope it will work.

Please try Open Solver. https://opensolver.org/
It is compatible with the Excel built-in solver, but it is much faster.
Excel built-in solver is always too slow.
Open Solver can get this model solved in seconds.

Thanks man,

It works!!!

I had Open Solver but it was not working on my model, but now it's 100 times faster than Excel built-in and it works.
I think main problem was that my type of model was too complex and I had to solve it using GRG, but now after refreshing the model it can be solved as Simplex (Linear).

Thank you very much for your time and help, I really do appreciate it a lot.

Cheers!

Hey,

I tried to change your model, by changing min & max constraint ranges, with the same 0.1 - 0.4 range for all or some other, but the open solver is running for ages without result. How can that be so, it works fine with our first type of constraints but it can't with any other. Or maybe it just want more time (hours)?

Thanks for your response Francesco, changing Branch & Bound tolerance helped a lot.