the BWE always exists when the OUT policy is used.
The results show that as long as the forecast error exists, the safety stock is needed and the BWE is unavoidable. However, correlation tests showed zero association between the forecast accuracy and the BWE.
Considering all obtained outcomes, the authors suggest that when the OUT policy is used, firms put efforts on managing the variation of the safety stock since the variation may be the major cause of the BWE, or that firms use other inventory policies.
Moreover, lead time and the responsive forecast also enhance the scales of the BWE.
The results imply that the firm should spend resources on minimizing the replenishment lead time and possibly stabilizing the demand variation.
Finally, although aggregation may help to reduce the BWE as proposed by previous efforts, our findings show that aggregate planning is not necessarily helpful to control BWE.
The findings further lead to the concern that aggregation is simply a fallacy which masks up the performance.