In looking at a Records Management solution for an organization, it is necessary to consider both physical records as well as electronic records. Ideally, the solution covers both, so that users can locate any record using the same interface regardless of type or format.
Managing electronic records is (relatively) straight-forward. Search for a record, then view it when (or if) it is found. The actual location is virtual and is transparent to the end user. The complexity comes in when you are designing the various capture methods for various types of electronic content, such as scanned images, office documents, email, instant messages, CAD files, GIS information and so on.
For physical records, you are recording the location of a record. Typically this is managed as collections of boxes rather than individual documents. This approach is used mostly because of the difficulties of adding document-level information to a database combined with typical lack of resources for this purpose.
Accessions of physical records is usually done in bulk, hopefully following guidelines related to box labels, box inventory lists, and so on. Physical records may also include microfilm, books, other media such as tapes and videos, three dimensional objects, and so on.
So the challenge of physical records management is complicated by the tracking process for records, including transfers, check in / check out, and storage locations. It includes "space management" in the most sophisticated solutions, which is a toolset for defining the available locations for records storage. This involves measuring the cubic feet of space on each shelf of a shelving unit, in a row of a storage facility. When you have an accession to move in, the toolset calculates the space needed and determines the best space to use for storage. This can get fairly complicated when you do not have contiguous space available, need to move material around, and so on.
Most records management solutions that are found in ECM suite products allow you to manage both electronic and physical records using the same tool. This is great, allowing users to search for any type of record using the same interface. If it is electronic, then they simply retrieve the record - which is indexed at the document level. If it is a physical record, the user sees the location including building address, row, shelf, bin and so on - or is notified that the record being sought is part of a collection of boxes stored at that location.
Most of these products do not have sophisticated physical records management features such as space management or advanced tools for box tracking using barcodes, RFID and so on. These features can be found in very specific physical records management products that are still - as of this writing - stand alone products.
You must weigh the advantages and disadvantages of the integrated solution for both electronic and physical records management against the fact that these products do not have the advanced features (yet) that you might need for physical RM.
Personnally, I opt for the integrated approach, since in my environment the space management and advanced tracking featues are not as important as having it all in one solution. I can see, however, in other very high volume demanding environments, why someone would take the other approach.