Technical Principles of SAP Business Workflow 
Technical Principles of SAP Business Workflow
The definition and execution of a workflow can be divided into four main areas. A user executes workflows in their Business Workplace where the work items that they are allowed to execute are displayed. A workflow must be defined to be executed. To this end, a workflow definition is created in the Workflow Builder. This definition contains steps that are executed at runtime. The steps either control the workflow directly or contain a reference to a task. The task refers to a method of an object type in the Business Object Repository (BOR) and can be executed at runtime either automatically (background task) or by a user (dialog task).
Business Workplace and work items
Work items are displayed to the user for execution in their Business Workplace. For example, work items represent a step at runtime that is to be executed. There are various types of work item. Only certain types are displayed in the Business Workplace.Workflow and workflow definition
You have to define a workflow before execution. This workflow definition is made up of steps that control the workflow or refer to the tasks to be executed. You can make additional specifications about agents and deadline monitoring for a step. These specifications are evaluated at runtime by the
work item manager. The workflow is started either manually by the user or by the system. For the system to start a workflow, the workflow definition must contain at least one triggering event (for example the event material created). When the event occurs, the relevant workflow is started automatically.When you activate a workflow definition, you automatically generate a runtime version. When the workflow is started (manually or automatically), the relevant runtime version is used for the execution. If the workflow definition is changed later and a new runtime version is generated, these changes do not affect workflows that are already being executed.
Tasks
Tasks describe elementary business activities. Tasks always refer to a method of an object type. Possible agents are defined for tasks. Tasks can refer to automatically executable methods (background tasks) or they can require a user to execute them (dialog tasks).
Object types and objects
An
object type describes the data with which you want to work in a workflow (for example the object type Material). An object is an individual data record of an object type. Attributes are defined for an object type, which make up its data record (such as material name, material number). Every object type has methods in which activities are defined that can be executed with the data (for example, create material). You can call the transactions and functions of the SAP System in a method, as can your own or other applications. Events are another important component of an object type. The events describe the status changes that an object can undergo (for example, material deleted or material changed). A workflow can be started by an event of this kind being triggered.The Business Object Repository provides an overview of all the object types in the SAP System. You can use or extend the existing object types as well as create new object types.