Sorry in advance sir/madam, it seems that the solver in excel is more concise and easier when completing the calculation of Mean Absolute Deviation (MAD), finding the optimal value (maximum, minimum, or certain target value), we just enter the cell object, then determine the cells whose values can be changed by the Solver (By Changing Variable Cells)
especially if the alpha value that has been determined such as 0.2 and 0.9, I think this is without a solver and by creating a simple formula such as = 0.2 * B2 + (1-0.2) * C2 where column B is the delivery order then column C is the forecast alpha 0.2, we have got the initial value, just drag the cell and later get the forecast value for the next period
However, it will feel a bit troublesome when completing ARIMA (Autoregressive Integrated Moving Average), why not just use VBA in excel?,
1- which is more flexible in setting logic, both for predetermined alpha or finding the optimal alpha value and is also easy to deal with more complex ARIMA
2. Automate the process forecasting.
3. Creating more customized and efficient solutions.
once again I apologize, this is just my opinion. If you want to keep using the solver, that's good, or want to create a special VBA for solving bakery delivery order problems, that's also good
don't hesitate to discuss with me.