A tip of a great tool.
Open solver is an Excel addin. It is very similar to the MS solver. The difference is that the default solver has a limit of around 5000 variables. Above this, the user has to purchase the Frontline solver (the name of the company).
To use opensolver, just download, unpack and add it to the Excel supplements.
A good evolution of openSolver is solverStudio, from the same developer. It allows a formulation of the problem using formulas, supports more optimization languages and is faster. But it is also a bit more complex to deal with.
Solver studio https://solverstudio.org
Both of these tools are able to use any solver. The package comes with CBC, the great open source solver from COIN-OR. https://www.coin-or.org/
Ideias técnicas com uma pitada de filosofia