What do you want to track?
I'd use XL and enter the key items for an investigation.
Off the top of my head:
Type of error (you may create a table of codes)
Amount of claim
Disposition of claim (again a table of codes or denote in progress, approved, approved other than as claimed, denied, withdrawn.
Date resolved (you could include other dates such as when you finalized the decision, paid a credit, debited an account, sent notification, etc.)
This depends on what you want out of the list. We had a list that was used to track the claims in progress, amounts paid and denied, etc. It wasn't to review claims. The file and investigators notes were needed for that. It was a database for stats and to trigger early warnings when trigger dates were approaching. You could do a query of all accounts approaching 8 or 40 days as an example.
My opinions are not necessarily my employers.
Rules and Regs minus Relationships equals Resentment and Rebellion. John Maxwell