I developed a document management system a while ago, however it can only handle the records of documents and those records are not directly linked to electronic documents which makes it far from optimistic.
By combining the system with sharepoint document library, the system can be used more regularly and reduce work load. i.e. create the document records and save a copy of documents under sharepoint document library, it can also be used to send transmittal electronically.
Thanks for the author of the following article:
I have been testing the solution and it seems to be working pretty well...