Chapter 3 Design Figure 3-13. Aggregator pattern • Business to business (B2B) architectures: There can be a scenario where you need to integrate business functions or processes available from third-party suppliers or business partners; for example, a bank provides billing and recharge functionality, hence the bank needs to integrate utility services from third-party suppliers. In this architecture we are integrating two system or business processes outside the organization. These systems are directly communicating with each other. • Service bus architectures (SOA): Shared business processes and functions also referred to as services. Once an organization collects a set of services, service bus architectures provide tools that make calling an external service almost as simple as using conventional methods. In this architecture all the services are communicating with the DXP’s application using a common bus, as shown in Figure 3- 14. Services from external system 1, external system 2, and external system 3 communicate with the bus, and these services are exposed to the DXP application via common bus. 81