BPMN

Introduction:

Business Process Model and Notation (BPMN) is a standard for business process modeling that provides a graphical notation for specifying business processes in a Business Process Diagram (BPD), based on a flowcharting technique.The objective of BPMN is to support business process management, for both technical users and business users, by providing a notation that is intuitive to business users, yet able to represent complex process semantics.

The primary goal of BPMN is to provide a standard notation readily understandable by all business stakeholders. These include the business analysts who create and refine the processes, the technical developers responsible for implementing them, and the business managers who monitor and manage them. Consequently, BPMN serves as a common language, bridging the communication gap that frequently occurs between business process design and implementation.

Elements of BPMN

• Flow Objects
• Connecting Objetcs
• Swim Lanes
• Artifacts

Flow Objects:

• Events
• Activities
• Gateways
• Connections

   Events

An Event is represented with a circle and denotes something that happens. Icons within the circle denote the type of event (e.g., an envelope representing a message, or a clock representing time).  Events are also classified as Catching (for example, if catching an incoming message starts a process) or Throwing (such as throwing a completion message when a process ends).

Start event

Acts as a process trigger; indicated by a single narrow border, and can only be Catch, so is shown with an open (outline) icon.

Intermediate event

Represents something that happens between the start and end events; is indicated by a double border, and can Throw or Catch (using solid or open icons as appropriate). For example, a task could flow to an event that throws a message across to another pool, where a subsequent event waits to catch the response before continuing.

End event

Represents the result of a process; indicated by a single thick or bold border, and can only Throw, so is shown with a solid icon.

   Activity

An activity is represented with a rounded-corner rectangle and describes the kind of work which must be done.

Task

A task represents a single unit of work that is not or cannot be broken down to a further level of business process detail without diagramming the steps in a procedure.

Sub-process

Used to hide or reveal additional levels of business process detail. When collapsed, a sub-process is indicated by a plus sign against the bottom line of the rectangle; when expanded, the rounded rectangle expands to show all flow objects, connecting objects, and artifacts.

Has its own self-contained start and end events; sequence flows from the parent process must not cross the boundary.

Transaction

A form of sub-process in which all contained activities must be treated as a whole; i.e., they must all be completed to meet an objective, and if any one of them fails, they must all be compensated (undone). Transactions are differentiated from expanded sub-processes by being surrounded by a double border.

Call Activity

A point in the process where a global process or a global Task is reused. A call activity is differentiated from other activity types by a bolded border around the activity area.

Gateway

A gateway is represented with a diamond shape and determines forking and merging of paths, depending on the conditions expressed.

Exclusive gateways

Exclusive gateway is a diversion point of a business process flow. For a given instance of the process, there is only one of the paths can be taken. See below business process diagram. If the order amount is greater than 1,000, we will request deposit from customer. If the order amount is 1,000 or less, we will deliver goods directly. There is only two possible path of the business process and these two possible paths will only execute one but not both

The suggested modeling of gateways is state the checking (question) in the gateway (diamond shape) and state the condition in the sequence flow. When the business process is executed (either by manual process or with automatic process), the condition will evaluate one by one and once the first condition is fulfilled, we still trigger the connected activity and stop evaluate other condition.

Inclusive gateways

Inclusive gateway is also a division point of the business process. Unlike the exclusive gateway, inclusive gateway may trigger more than 1 out-going paths. Since inclusive gateway may trigger more than 1 out-going paths, the condition checking process will have a little bit different then the exclusive gateway. All out-going conditions will be evaluated no matter has fulfilled out-going flow or not. Below business process diagram show a typical inclusive gateway usage.

Following are all possible paths of the business process

1. Ship all goods by air
2. Ship all goods by sea
3. Ship some goods by air and others by sea.

Event-Based Gateway

Event-Based Gateway is similar to exclusive gateway but the trigger of gateway is base on event occur instead of evaluate condition. We can imagine when our process arrived to event-based gateway, we will wait until something is happen. The event usually trigged by third party (e.g. our customer send payment to us). Below is typical event-based gateway. We send a quotation to customer and waiting for customer to confirm the order. If customer sends confirmation, we will prepare goods for customer. If we don’t receive any confirmation from customer after 15 days, we will send reminder to customer.

           

        Parallel Gateway

           A parallel gateway is used to visualize concurrent execution of activities. When the process arrive to parallel gateway node, the work will split into multiple token and will merge when reach to the joining parallel gateway. Bellow is the typical example of parallel gateway.