How a manufacturing and service business would benefit from enterprise resource planning (ERP)

Consider a manufacturing and a service business you know that would benefit from enterprise resource planning (ERP) or from materials resource planning (MRP) improvements. What specifically would the ERP fix in each case (manufacturing and service arenas) and how will the organizations get payback from implementing the ERP changes? What hidden costs would you caution higher management to consider in each case? Investigate the scholarly literature on ERPs beyond the course material.