This is an MPS problem.

Backorder is not allowed, so PAB value at week 5 cannot be negative. If MPS cannot be added or changed in slushy zone, how do we get a positive value for PAB at week 5? Show all steps and explain please

\begin{tabular}{|c|c|c|c|c|c|c|c|c|c|c|} \hline \multicolumn{2}{|l|}{ Week } & 1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 & 9 \\ \hline \multicolumn{2}{|l|}{ Forecast } & 20 & 20 & 20 & 30 & 30 & 25 & 25 & 30 & 40 \\ \hline \multicolumn{2}{|l|}{ Orders } & 25 & 23 & 12 & 18 & 16 & 10 & 5 & & \\ \hline Projected Available Balance & 20 & 40 & 17 & 5 & 25 & -5 & 25 & 0 & 20 & 30 \\ \hline \multicolumn{2}{|l|}{ Available to Promise } & 5 & & & 16 & & 35 & & 50 & 50 \\ \hline \multicolumn{2}{|l|}{ MPS } & 45 & & & 50 & & 50 & & 50 & 50 \\ \hline & & \multicolumn{3}{|c|}{ Frozen Zone } & \multicolumn{2}{|c|}{ Slushy Zone } & \multicolumn{4}{|c|}{ Liquid Zone } \\ \hline \end{tabular}