The complexities arise from handling multiple standards, costing requirements, depreciation treatments, taxation, cost centers, profit centers, endless libraries of relationships between invoices and amortization, recurring payments ... I could go on for another two pages without even touching on consolidation and ownership rules.
The double ledger system visualised as a simple T is accounting’s irreducible component. But the system necessary to maintain not just a ledger of record, but to do it with accuracy, ease and maintain the ability to extrapolate necessary reporting for management and decision making is a far more complex and often needs custom design. Multiple overlapping requirement from compliance, audit and m&d also add complexities.
Edited to answer your question: unfortunately I am not aware of an open source solution. Depending on the size of your organization, you may need to look at designing a custom solution that integrates consolidation, ledger entry and reporting. Most small to medium enterprises can however get by with out of the box solutions from SAP or Oracle. Microstrategy is also useful.
Source: former systems analyst
