An integrated Enterpise Resourcing and Planning (ERP) system usually includes company, financial and accounting information, operational information, and customer relationship management (CRM) information. An integrated system is always preferable to a hodge-podge of stand-alone systems. It is extremely complex to integrate stand-alone systems that were not designed to be integrated, and the results of this type of integration are usually inadequate and expensive.

In large companies with extremely complex requirements, integrated systems may not meet the requirements. In these cases, specialised, non-integrated systems may be required. Examples of this are MRP (Materials Resource Planning); Complex Manufacturing; Industry specific solutions and Complex Warehouse Management. It is sometimes better to select ‘best of breed’ specialised software and limit the integration to financials only (i.e General Ledger, Debtors and Creditors).