Department of Computer Science 1 CSS 496 Business Process Re-engineering for BS(CS)

Department of Computer Science 2 Business Process Modeling Notation (BPMN) Developed by Object Management Group We will focus only on main concepts It combines the best approaches of all other process modeling languages (graph-based, petri-nets, Event driven process chain, UML activity diagrams) The main purpose is to facilitate all levels of business and software systems

Department of Computer Science 3 Components of BPMN Core components: Events, activities, gateways, sequence flow

Department of Computer Science 4 Details of BPMN notations Events: Occurrence of something that is relevant for the business Activities: The performance of work Gateways: represent the joining and splitting of flow during the business process Swimlanes: divided in two components, i.e., pool and lanes. 1. Pool: To define the boundary between two businesses 2. Lane: to define the boundary between different organizational entities, such as departments

Department of Computer Science 5 Details of BPMN notations (Cont.) Artifacts: include additional information such as data objects, annotations, groups 1. Data objects: for documentation purposes to represent which data object, file has been created or modified by an activity 2. Annotations: text for explanation 3. Groups: for documentation purpose to show which elements are in a group.

Department of Computer Science 6 Details of BPMN notations (Cont.) Connecting objects 1. Sequence flow: To show the flow or sequence between elements of process model 2. Message flow: To show the message passing between businesses 3. Association flow: For linking artifacts with elements of process model

Department of Computer Science 7 Example

Department of Computer Science 8 Events types Mainly divided in three parts, i.e., start, intermediate (occurs between the process, can delay execution), end events

Department of Computer Science 9 Start Event triggers None: does not have a defined trigger, can be used when a process invokes a child process User: A user triggers an event Message: Triggers on receiving a message Timer: occurs on a specific time Rule: occurs when a particular rule evaluates to be true Link: Connecting end of a process and start of the other process Multiple: Means multiple ways are available to start it. Only one condition needs to be true

Department of Computer Science 10 Intermediate Event triggers None: can highlight the change of state in the process, e.g., investigation event Message: Wait for a message to continue Timer: Starts on a specified time Error: To handle exceptions or alternative flows investigation Report

Department of Computer Science 11 End Event triggers None: end event with no information Error end: End with an error or for raising exception to be caught by intermediate event Terminate: To immediately end the process

Department of Computer Science 12 Activities Activities are units of work Atomic Activities: It means the internal structure or sub-processes are not important for modeling, atomic activities are called tasks Types of tasks: 1. Receive tasks: waits to receive a message 2. Send tasks: opposite of receive task 3. User tasks: performed by user 4. Reference tasks: can be reused in modeling different processes

Department of Computer Science 13 Gateways Used to merge or split the flow Data-based gateways, Event-based gateways (waiting for a message or something to happen) Symbols

Department of Computer Science 14 Gateways (Cont.) XOR Split: Can follow one flow XOR Merge: Only one input is chosen to be output from the gateway Inclusive OR Split: One or more path can be taken, cannot be zero path you must specify a default path Inclusive OR Merge: One input is required to continue Complex merge gateway: involving a complex expression, e.g., flow A and B are required to continue or it can also work alone with C Complex split gateway: complex expressions, opposite of complex merge gateway AND Split: All paths are chosen AND Merge: Signals from all paths are required