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 Gateways Used to merge or split the flow. The decision is not made at Gateway rather it is just a router depending on its previous activity Data-based gateways, Event-based gateways (waiting for a message or something to happen) Symbols

Department of Computer Science 13 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 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

Department of Computer Science 15 Example BizAgi

Department of Computer Science 16 Example Here please notice the intermediate event (external factor) “Receive Document”. It is an event because it has been submitted by the client and not generated by the employee of the organization. “Receive Document” basically represents that sometimes the client does not submit all documents at the beginning but at some later stage. The completion of documents is necessary for further processing of application. The intermediate event here represents it.

Department of Computer Science 17 Example with timer

Department of Computer Science 18 Example:

Department of Computer Science 19 Example: Shipment process of a hardware retailer

Department of Computer Science 20 Example: Pizza Delivery

Department of Computer Science 21 From Spec.

Department of Computer Science 22 From Spec.

Department of Computer Science 23 Example

Department of Computer Science 24 Example

Department of Computer Science 25 Event Driven Process Chain This notation is used in ARIS (Architecture of Integrated Information Systems) ARIS House or ARIS main building blocks (please see the slides of Prof. Scheer) 1. Control View: integrate other views modeled by EPC 2. Functional View: Identifies goals/sub-goals and functions that need to be performed to achieve them 3. Data view: Business related data that will be used by functions 4. Input-Output View: deals with the input and output of the business 5. Organizational View: The entities that are performing functions. complete hierarchal structure of the organization. It can encompass organizational units, individuals, roles, skills and even about information systems, storage facilities, network infrastructure.

Department of Computer Science 26 Event Driven Process Chain (cont.) Three Abstraction in each View of ARIS 1. Requirement Specification: identification of goals, sub-goals, functions (function view), EPC (control view), Entity relationship diagrams (data view), Organizational diagrams (organization view) 2. Design Specification: technical requirements, architecture level description 3. Implementation Details: deals with actual implementations, hardware-software related

Department of Computer Science 27 Event Driven Process Chain (cont.) EPC Details 1. Event: change of state in an object 2. Functions: units of work 3. Connectors: for flow control

Department of Computer Science 28 EPC Details (Cont.) Functions trigger events and events trigger functions Function transforms input into output Events cannot make decisions via connectors

Department of Computer Science 29 Syntax rules The arrows marked as cross are wrong. Correct their direction towards events

Department of Computer Science 30 Syntax rules (cont.)

Department of Computer Science 31 Example

Department of Computer Science 32 Example of extended EPC