The OBS Booking Engine not only caters for a freely definable chart of accounts, but also for the variable allocation of the booking entries to the accounts. This ensures that, for example, the financial books can be trade date based as well as value date based.

The accruals and valuations of income and expenses are done within each individual OBS module and the booking entries are automatically passed to the OBS-REW module through the booking engine. In general all products in OBS are valued on a mark-to-market basis and, where relevant, on a lowest-value-principle.

Due to its ability to effectively communicate with other software systems OBS-REW can import foreign data and export data to third-party systems e.g. controlling systems, fixed asset systems, accounts payable / receivable systems, etc.