Bahmni integrates OpenMRS with OpenERP which is a an open source ERP product. It is useful in Billing, Stock management. Any patient registered in OpenMRS is synced as a customer in OpenERP. Any Drugs, LabTests added in OpenMRS is synced as product / service in OpenERP. When Doctors place any order, it syncs in OpenERP as Sales Quotation so that the patient can be billed.