A Simple Process represents the internal processes that occur within one organizational unit or business entity. These are sometimes referred to as workflow processes. In Web services, they are referred to as orchestration of services. If swimlane notation is used, the process is contained within a single pool, which is assumed and therefore not shown in the diagram. Simple Processes can include multiple lanes to represent roles or internal participants in the process.
A Business2Business Process represents global processes that span more than one organizational unit or business entity. This process is represented by multiple swimlane pools. Message flows connect the activities across the pools.