E-Commerce systems are characterized by complex Web applications that use different operating systems and different technologies. One of the most popular E-Commerce applications is conducted between businesses (B2B) and between a business and a consumer (B2C) is Purchase Order Management. It consists of components such as Sales, Shipping and Billing. In many cases nowadays Purchase Order Management components use integration approaches that lack interoperability and manageability resulting in customer dissatisfaction, time consumption and excessive costs. In this research, we build a model to overcome shortcomings of current Purchase Order Management system. The model is based on the Service Oriented Architecture (SOA) principles, Enterprise Service Bus (ESB), and Web services. They offer many advantages and help achieve the goals of interoperability and manageability. The proposed model is evaluated by using a scenario based software architecture method and proves that it achieves the quality attributes set as goals for the model which are interoperability and manageability. A case study of the model is implemented as a prove-of-concept. A specific usage scenario for the model is discussed and further proves that the model accomplishes its functionality and quality attributes
