The Question
How can I create a Calculated column with a formula that works the same way as an Excel MAX formula?
Why
I have a need to create unique ID's for process documents, but can't rely on the inbuilt ID field becuase if you delete a record SharePoint still reserves the ID for it. So there are no gaps in the set of Process Numbers I need to manually create this number.
Obviously I can do this by restricting entry of the number field to unique numbers but this wouldn't stop someone from entering 50 when there are only 30 records.
So ideally I was hoping to set the ProcessNumber field's default value as the result of =MAX(ProcessNumber)+1, but I have no idea how to.