# Understanding the terminology ## BPMN and SpiffWorkflow Business Process Model and Notation (BPMN) is a diagramming language for specifying business processes. BPMN bridges the gap between business and IT, creating a shared process language for both parties. BPMN efficiently depicts the details of process behaviors in a diagram. The precision of its meaning allows it to describe the technical details that control process execution in an automation engine. SpiffWorkflow enables you to create code to execute a BPMN diagram directly. By using SpiffWorkflow, a client can create the BPMN diagram and have their product work without the need for you to modify the Python code, thus improving response and turnaround time. ## Flow Objects Flow objects are divided into three groups: Events, Gateways, and Tasks. ### Events Events, represented by circles, describe occurrences during a process. There are three main types of events in business process modeling: start events, intermediate events, and end events. | **Event** | **Symbol**| **Description** | |-----------|-----------|-----------------| | Start Event | | Signals the first step of a process. | | Intermediate Event |  | Represents any event that occurs between a start and end event. | | End event |  | Signals the final step in a process. | ### Gateways Gateways represent decision points in a process. Based on certain conditions or rules, they determine which path the process will follow. There are various types of gateways: | **Gateway** | **Symbol**| **Description** | |---------------|-----------|-----------------| | Exclusive gateway | | Evaluates the state of the business process and, based on the condition, diverges the flow into one or more mutually exclusive paths. | | Event-based gateway |  | An event-based gateway is similar to an exclusive gateway in that both involve one path in the flow. However, with an event-based gateway, you evaluate which event has occurred, not which condition has been met. | | Inclusive gateway |  | An inclusive gateway diverges the process flow into one or more flows. | | Complex gateway |  | Complex gateways are used only for the most intricate flows in the business process. They use words instead of symbols and thus require more descriptive text. | ### Tasks Tasks represent activities or work that needs to be done as part of a process. They can either be manual tasks that require human intervention or automated tasks that are performed by systems or applications. | **Task** | **Symbol** | **Description** | |---------------|------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | Service |  | A task that utilizes a Web service, an automated application, or other types of service to complete the task. | | Send | | A task that sends a message to another pool. The task is completed once the message has been sent. | | Receive |  | A Receive Task indicates that the process has to wait for a message to arrive in order to continue. The task is completed once the message has been received. | | User |  | A User Task denotes that a human performer completes the task with the help of a software application. | | Manual |  | A Manual Task is a task performed without the aid of any business process execution engine or application. | | Business Rule || A Business Rule Task provides a mechanism for a process to supply input to a Business Rules Engine and then obtain the output provided by the Business Rules Engine. | | Script |  | A Script Task defines a script that the engine can interpret. | | Call Activity |  | A call activity allows you to call and invoke another process as part of this process. | | Sub-Process |  | Sub-processes allow you to collapse and expand tasks to convey information quickly. | ## Connecting Objects Connecting objects are lines that connect BPMN flow objects. Three different types exist: sequence flows, message flows, and associations. | **Connecting Objects** | **Symbol** | **Description** | |---------------|------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | Sequence flow symbol |  | Connects flow objects in the proper sequential order. | | Message flow symbol | | Represents messages sent from one process participant to another. | | Association symbol |  | Illustrates relationships between artifacts and flow objects. | ## Artifacts Artifacts are used to provide additional information or documentation within a process. They include data objects (which represent information or data needed for the process), annotations (which provide explanatory or descriptive text), and groups (which are used to visually group related elements). | **Artifact** | **Symbol** | **Description** | |---------------|------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | Data Object |