Ok I’m starting off to clarify this is a hack/backdoor/”workaround” and of course not supported by Oracle development or support or anyone associated with Oracle, ie you are on your own!  So why am I telling you? its one of those tricks that can be pulled out when you need a quick cheap and temporary solution. 

The SLA upgrade flag’s intended use is to bypass the “regular” logic and use “upgrade” logic.   There are two features in SLA, Business Flows and Reversals that require previous accounting to be present in SLA tables in the “regular” logic.  The upgrade logic does not do the look back.  This feature is used by Federal and Public Sector SLAMs seeded in R12.

Why is this cool? you can use this to change SLAMs, on seeded rules this will work if you are changing to the seeded Federal and Encumbrance SLA rules, you will not have to worry about SLA erroring out or having to create the “missing” SLA journals. 

You can also use this for your custom rules if you happen to have a specific case where you want to bypass the “regular” SLA logic.  Though consider using SLA JLT conditions first!  There are hundreds of sources and you can add more via reference objects, however for a quick and temporary fix you may want to try this.