One of the most resource intensive functions in a chart is the If statement. In a lot of scenarios, what you can do is leverage the combination of Pick and Match to replicate the functionality while increasing performance.
Example:
If([Inventory Type]='Individual', Sum(Qty), If([Inventory Type] = 'Bulk', Sum(BulkQty)))
Pick(Match([Inventory Type],'Individual','Bulk'), Sum(Qty), Sum(BulkQty))
If you need an Else condition, there is a neat little trick you can do by adding a ‘+1’ and making the first option the Else result:
Pick(Match([Inventory Type],'Individual','Bulk')+1, 'Non-Physical Item', Sum(Qty), Sum(BulkQty))