Yes, it seems you have been already answered...
Just to expand the horizons..
ERP (Enterprise Resource Planning) systems are supposed to manage/automate almost all the critical business activities of large-scaled businesses.
Generally, an ERP system includes modules like Production, HRM (Human resource management), CRM (customer relationship management), Finance, Logistics, Payroll, Inventory, SCM (Supply-Chain management), etc.
nowadays it is rare to hear that companies build them from the scratch. (But there are companies in SL who are having built ERP systems from the scratch..I mean software dev companies those who specialized in ERP systems) Instead, people use ERP platforms like SAP and extend their functionalities through scripting. (without re-inventing the wheel)
by the way, ERP systems are considered to be complex systems.