Overview

The primary goal of BPMN is to provide a standard notation that is readily understandable by all business stakeholders. These business stakeholders include the business analysts who create and refine the processes, the technical developers responsible for implementing the processes, and the business managers who monitor and manage the processes. Another important goal is to visualize through business-oriented notation such XML languages as BPEL4WS (Business Process Execution Language for Web Services), designed to execute business processes.

This standard discloses the concept and defines the semantics of Business Process Diagram (BPD) and combines the best practices developed in the field of processes’ modeling. The purpose of BPMN is to unify business processes modeling standards when there are many different standards and point of view on modeling.

There are two main aspects of the BPMN specification:

The external view of graphical elements. The key moment of BPMN is a choice of shapes and icons used in graphical elements. The goal is to create a standard visual language that will be recognizable and understandable by all developers of processes, regardless of the source of diagram.

The semantics of BPMN elements. This language also defines how graphical elements interact with each other, including conditional interactions based on the attributes that create behavioral changes of the elements. Compliance tool should be correlated with these semantic descriptions.

BPMN topics

BPMN is constrained to support only the concepts of modeling that are applicable to business processes. This means that other types of modeling done by organizations for non-business purposes will be out of scope for BPMN. For example, the modeling of the following will not be a part of BPMN:

• Organizational structures and resources

• Functional breakdowns

• Data models and informational models

• Strategies

• Business rules

In addition, while BPMN will show the flow of data (messages), and the association of data artifacts to activities, it is not a data flow diagram.

BPMN appointment

Business processes modeling is used to communicate a wide variety of information to a wide variety of audiences. BPMN describes many types of modeling and allows modeling of end-to-end business processes. The structural elements of BPMN make it easy to differentiate between sections of a BPMN Diagram.

There are three basic types of sub-models within an end-to-end BPMN model:

• Private (internal)business processes

• Abstract (public) processes

• Collaboration (global) processes

Private (internal)business processes

Private business processes are those internal to a specific organization and are the type of processes that have been generally called workflow or BPM processes. A particular business process can be displayed in one or more documents, but under all circumstances it must be completed within the organization.

Abstract (public) processes

These represent the interactions between a private business process and another process or participant. Only those activities that communicate outside the private business process are included in the abstract process. All other “internal” activities of the private business process are not shown in the abstract process. Thus, the abstract process shows to the outside world the sequence of messages that are required to interact with that business process. Abstract processes are contained within a Pool and can be modeled separately or within a larger BPMN Diagram to show the Message Flow between the abstract process activities and other entities. If the abstract process is in the same Diagram as its corresponding private business process, then the activities that are common to both processes can be associated.

Collaboration (global) processes

A collaboration process depicts the interactions between two or more business entities. These interactions consist of the message exchange patterns between the entities involved. The same collaboration process can be charted to the diagram in various languages.

Collaboration process can be depicted as two or more interacting abstract processes. Activities of participants of the joint work can be regarded in the abstract process as “a touch point” between the participants. Actual (running) processes, in fact, are more detailed and consist of lots of actions comparing with abstract processes.

Types of Diagrams

Within and outside these three BPMN sub-models many types of Diagrams can be created. The following are the types of business processes that can be modeled with BPMN:

• High-level private process activities (not functional breakdown)

• Detailed private business process

• As-is or old business process

• To-be or new business process

• Detailed private business process with interactions to one or more external entities (or “Black Box” processes)

• Two or more detailed private business processes interacting

• Detailed private business process relationship to Abstract Process

• Detailed private business process relationship to Collaboration Process

• Two or more Abstract Processes

• Abstract Process relationship to Collaboration Process

• Collaboration Process

• Two or more detailed private business processes interacting through their Abstract Processes

• Two or more detailed private business processes interacting through a Collaboration Process

• Two or more detailed private business processes interacting through their Abstract Processes and a Collaboration Process

BPMN is designed to allow all the above types of Diagrams. However, it should be cautioned that if too many types of sub-models are combined, such as three or more private processes with message flow between each of them, then the Diagram may become too hard for someone to understand. Thus, we recommend that the modeler pick a focused purpose for the BPD, such as a private process, or a collaboration process.

Business process diagram

A set of basic graphical elements of business process diagram
It should be emphasized that the one factor of BPMN development is to provide a simple mechanism for business processes modeling, capable to manage complex business processes at the same time. The way to solve the problem of combining these two conflicting requirements was to create graphics with specific categories. The set of categories in this notation is small, so the reader of BPMN diagram can easily recognize the basic types of elements and understand the diagram. Within the major categories of elements additional changes and information can be added to ensure the compliance with the complexity requirements without significant changes of the basic perceptions and impressions of the diagram.

Four main categories of elements can be distinguished:

• Flow Objects

• Connecting Objects

• Swim lanes

• Artifacts (Artefacts)

Flow objects – the core graphical elements, which are used to determine the development of a business process. Three objects can be distinguished:

• Events

• Activities

• Gateways

There are three ways to connect objects with each other or with other information. One can distinguish three connecting objects:

• Sequence Flow

• Message Flow

• Association

There are two ways of grouping the basic modeling elements through “lanes”:

• Pool

• Lane

Artifacts are intended to bring additional process information. There are three pre-defined Artifacts, but a developer or a modeling tool can add as many artifacts as required. BPMN can take extra effort to bring a large set of artifacts to a single standard for general use or for vertical markets. This set of artifacts includes:

• Data Objects

• Group

• Annotation

The list of the basic modeling elements, which are described in the notation, follows below:

Basic modeling elements

Element	Description	Notation
Event	An event denotes something that “is happening” during the business process. Events affect the course of a business process and usually have a trigger or the result. Events are represented with circles with open center to allow internal markers to distinguish between different triggers or results. There are three types of events, classified according to exposure time on the process: Start event, Intermediate event, End event
Activity	An Activity – a term to describe the kind of work performed by the company. The activity can be elementary or nonelementary (component). Types of activities, which are a part of the process model: Process, Sub-process, Task. Tasks and sub-processes are reprented with rounded-corner rectangles. Processes are either unlimited, or contained within the pool.
Gateway	A Gateway is used to control forking and merging of Sequence Flow. Thus, it will determine forking, splitting, merging and connection of paths. Internal markers will indicate the type of control of the process development.
Sequence Flow	A Sequence Flow shows in which order the activities of the process will be performed.
Message Flow	A Massage Flow represents the flow of messages between two participants, who are ready to send and receive them. Two separate pools on the diagram will represent two participants in BPMN (for example, business entities or business roles).
Association	An Association is used to associate information with objects. Text and graphical objects which are not included to the chart can be related to Flow objects.
Pool	A Pool represents major participants in a process. It also plays the role of “lanes” and a graphical container for separating a set of activities from other pools, usually in the context of “business to business” situations.
Lane	A Lane is a subsection within a pool; it is stretching the width or height of the pool. Lanes organize and categorize activities.
Data Objects	Data Objects are regarded as artifacts because they don’t directly affect the Sequence Flow or the Message Flow of the process, but they provide information input about which activities should be performed and / or what they produce..
Group (a rectangle around a group of objects for the purpose of documentation)	Grouping of different activities, which don’t affect the Sequence Flow. Grouping can be used for documentation purpose or analysis. Groups can also be used to detect activities of an operation, which is distributed over the width of the pool.
Annotation (connected with the Association)	A Text Annotation is a way to provide additional information to a person reading the BPMN model.