We are using BSI TaxFactory here at our installation on 40B, and have been live since 5/99 on payroll. There are no other options for US payroll in SAP that we are aware of. Our environment is very simple: one plant, one state, no sub-state income tax jurisdictions.
As a BASIS person, I do not like the maintenance updates, which come out 2-4 times a month, and which must be applied faithfully in sequence regardless of whether they pertain to our company or not. Corresponding SAP updates are downloaded from the SAP ftp server in special SAP transports 2-4 weeks after the BSI updates are delivered by email. The BSI component is essentially a "black box" application about which we know nothing of the internals.
In the past, the BSI server had to be installed on another platform (NT) and accessed via a SAP standalone gateway, but that is (thankfully) no longer true. There is now an AS/400 server for BSI TaxFactory, which we began using in late December (after a month-long struggle to get through a faulty installation.)
Some other issues I have are more related to the general topic of in-house payroll, not specific to BSI, but rather to the SAP environment and the number of transport requests that the HR-payroll department seems to need in order to make payrolls happen. If you are used to running your own payroll systems, then perhaps this is not news, but there is a great deal of change in personnel and especially payroll systems.
To get to the point: BSI TaxFactory does work with SAP on the AS400. The TF60 database resides on the AS400, and the server is an AS400 program. There is TCP RFC communication to the BSI server. The current version 6.0 has a structure which corresponds to the SAP system client orientation. For each SAP client number using payroll, the TaxFactory server must have a defined "dataset" of the same number. Each dataset (client) can have different table data. Multiple BSI servers can be set up, and I plan to implement a second server in order to have a separate BSI server to test updates, upgrades, and configuration changes. We have not had any end-user department access to the BSI tables so far in the time that BSI has been installed. BSI table updates are applied by BASIS as necessary through the TaxFactory admin "client" update program (installed on a Windows platform). Some updates (to a BSI mapping table) must be made manually through the TaxFactory admin client (since version 6.0), having to do with new tax jurisdictions. Info for those updates are provided by SAP as text files which accompany the SAP update transports on sapserv4. The SAP updates are applied through special transports downloaded via ftp from sapserv4, and imported into each SAP system (DEV, QAS, TST, PRD). There may also be payroll department client-specific activities to cascade updates from client 000 to the useful client(s).
I hope this provides some clarity. If so, good. If not, I can try to address issues specifically. There is very little that is straightforward.
Regards, Steve Chapman California Steel Industries, Inc