I think we'd need to see your data model to determine exactly what the issue is, but it sounds like there's some duplication in your data. Maybe you have duplicate employee or warehouse records. If these are being used in your chart then that could account for incorrect results.
If you're not able to share your data model, I'd suggest making your dimension loads LOAD DISTINCT.
Thanks for the reply, appreciate it!
The LOAD DISTINCT works! However this prompts me to wonder why there are duplicates in the data as when I create a Table Box, I don't see any duplicates. I remember reading somewhere on the forum and also seeing first-hand that the table box excludes duplicated rows - is this true?
If it is true, what is the best way of seeing what the loaded data actually looks like? As I've been using Table Box to have visibility of the data tables.