Missing BSFN in E9.1 - B0800387

I wanted to share my 9.1 findings with you. There is a missing business function in E9.1 - B0800387. I was able to locate an equivalent one but the required functionality is not there. i.e B0800144. Has anyone run into this scenario? B0800387 is currently used in a custom program. Would anyone recommend if it would be advisable to bring it over or should we create a custom one in 9.1

So, implied in your statements is that you're doing a upgrade for an older version to 9.1.
Its entirely possible that Oracle has obsoleted an object so that its no longer in a later release. Particularly if you're coming from a very old release.