Although Boeing and Rolls-Royce are operating in the same aerospace industry sector and use ERP, but the ways that they implemented their systems are completely different. Boeing uses big bang and treats ERP as a system implementation, whilst Rolls-Royce uses phased implementation and treats ERP as a philosophy. Both companies experience different outcome as a result of their approaches. (Koh, 2006) Dell has a “build-to-order” business model that clearly integrates both supply and demand chains. That model has worked astonishingly well for Dell, its customers and its key suppliers. In fact, Dell could not do what it does if it designed and managed its supply chains and Customer Relationship Management (CRM) as separate technical entities. The “build-to-order” business value proposition demands an architecture that inherently integrates customers and suppliers. Yes, Dell has a “supply chain,” but it coevolves in the context of explicit customer demand. (Gunasekaran and Ngai, 2005).