Answer
Organizations that do fine inside the ERP typically have a single entity or a small number of straightforward entities, a close process measured in days rather than weeks, and audit requirements the built-in general ledger and reporting tools already satisfy without heavy customization. The financial layer inside most IBM i ERPs handles standard GL, AP, AR, and fixed assets competently, and replacing it purely for a more modern interface rarely justifies the migration cost and risk.
The harder cases involve multi-entity consolidation, complex intercompany eliminations, statutory reporting across jurisdictions, or audit and controls requirements that the ERP's finance module was never built to handle gracefully. Before assuming a dedicated platform is the answer, buyers should document the specific reports, controls, or close-cycle steps that are actually broken today, then check whether the ERP vendor has closed that gap in a version the organization has not yet adopted, since IBM i shops sometimes stay several releases behind and miss functionality that already exists. If the gap is real and current, evaluate a dedicated financial platform against how well it integrates back to the ERP for operational data, not just its standalone feature list, since a best-of-breed finance system that cannot reconcile cleanly with production order and inventory data just moves the problem instead of solving it.