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CSS 496 Business Process Re-

engineering for BS(CS)

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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

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Components of BPMN Core components: Events, activities,

gateways, sequence flow

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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 businesses2. Lane: to define the boundary between different

organizational entities, such as departments

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Details of BPMN notations (Cont.) Artifacts: include additional information such

as data objects, annotations, groups1. 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.

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Details of BPMN notations (Cont.) Connecting objects1. 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

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Example

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Events types Mainly divided in three parts, i.e., start,

intermediate (occurs between the process, can delay execution), end events

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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

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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

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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

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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

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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

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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

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Example BizAgi

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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.

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Example with timer

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Example:

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Example: Shipment process of a hardware retailer

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Example: Pizza Delivery

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From Spec.

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From Spec.

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Example

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Example

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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 EPC2. Functional View: Identifies goals/sub-goals and functions that

need to be performed to achieve them3. Data view: Business related data that will be used by functions4. Input-Output View: deals with the input and output of the

business5. 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.

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Event Driven Process Chain (cont.) Three Abstraction in each View of ARIS1. 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

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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

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EPC Details (Cont.)

Functions trigger events and events trigger functions

Function transforms input into output Events cannot make decisions via connectors

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Syntax rules

The arrows marked as cross are wrong. Correct their direction towards events

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Syntax rules (cont.)

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Example

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Example of extended EPC