Right now, the forecast report automatically accounts for the stock of all products across all sites. It would be more useful if users could decide what sites are considered when determining stock levels, though.
Stock being held in a 3pl warehouse on the other side of the country can cause forecasting issues. For example, if the forecast report says you have 50 kegs of IPA and only need 45 for the next week, you might think there is no issue, only to find out that those 50 kegs are in 3pl warehouses and unuseable.
The best solution would be to add a filter to the report that allows you to designate what sites’ stock is considered. This would have the added functionality of being able to forecast each site’s stock levels individually, based on forecasts you’ve made for each location.