This setting is only available if you have selected the Turnover rate list type. It is used in the list in order to also be able to save the calculated turnover ration per part in the range of parts. The turnover ratio is the turnover rate of a part.
The calculated turnover ratio that has been saved can then be viewed in the Planning tab in the Part Info and Update Part - Inventory procedures. They can also be viewed in the Inventory Value List.
Please note that the safety stock and EOQ can be changed in the list in order to be able to analyze the effects on the turnover rate with changed quantities of the safety stock and EOQ. This means that with this alternative activated, a modified turnover ratio will be saved in case the safety stock or EOQ is changed and the list is saved. However, this can be reset by reloading the list and then save it again, since the safety stock and EOQ will not become updated.