Understanding BPMN
Business Process Modeling Notation (BPMN) was created to represent
work processes in diagrams that are readily understandable by business
people, yet are rich enough in detail to allow IT departments to
translate process maps into technical specifications. The goal for BPMN
is to enhance communication about processes across an organization. For
automated processes, BPMN diagrams can serve as a bridge between process
participants and the IT staff that build systems to support their
work.
At one level, a BPMN diagram is like a flowchart or swimlane
diagram. However, the symbol set is significantly larger than the one
used for a conventional flowchart or swimlane diagram. This one fact
leads both to strong advocacy for and strong resistance to BPMN.
Advocates assert that it is the combination of visual richness and
underlying data attributes that allows BPMN diagrams to convey complex
system and human interactions. Critics complain that the sheer number of
symbols and symbol variants is off-putting to many people; they feel it
makes diagrams more complex and less understandable to the business
people who are half of the intended audience for BPMN.
The creators of BPMN have worked hard to make BPMN usable by a
larger number of people. One result is that BPMN 2.0 defines a smaller
working set of shapes and symbols that will be familiar to anyone who
has created traditional flowcharts. However, Visio Premium 2010
implements BPMN 1.2 and does not, therefore, include the smaller working
set. Having more shapes available in BPMN 1.2 is not inherently a bad
thing, but the number of shape variations can be confusing.
The first thing to know about creating BPMN 1.2 diagrams from the
Visio Premium 2010 template is that there are four core shape types:
Events,
Activities, Gateways, and
Connecting
Objects, with multiple variations of each.
The BPMN 1.2 symbol set includes the following:
-
Three types of Events, classified as Start, Intermediate, and
End, and represented by different kinds of circles.
There are five subtypes of Start events, eight
Intermediate events, and seven End events; each subtype is
represented by a symbol inside one of the circle variants.
-
Two Activity types, tasks and subprocesses, each of which has
multiple variations.
-
Six Gateway types.
-
Three Connector types, representing sequence flows, message
flows, and associations between shapes, with several condition
attributes for sequence flows and direction attributes for
associations.
If you create process documentation in any form today, or expect
to in the future, it is worth learning more about BPMN.
Creating and Validating BPMN Diagrams
Important
The Visio BPMN template supports version 1.2 of the BPMN
standard.
Microsoft provides five stencils with the Visio 2010 BPMN
template. The key masters in the first stencil, BPMN Basic
Shapes, include the primary Event types described in the
previous section, a generic Gateway, and a basic Activity type called a
task (see the graphic on the left). The other four
templates present all of the variations of one shape category. In the
center and right graphic, you see the Gateways and Connecting Objects,
respectively.
Although the five templates provide every possible BPMN
map variant as a separate master in a stencil, it’s important to know
that all of the BPMN shapes are chameleon-like shapes. For example, you
can right-click any Activity shape to transform it into any other
Activity type. The same is true for Events, Gateways, and
Connectors.
In this exercise, you will start with a partially completed BPMN
diagram of a theater box office ticketing process. You will set a
trigger for the start event that launches the process, add a task and a
gateway to offer the purchaser alternatives if the requested seats are
unavailable, and set BPMN subtypes for various shapes.
Set Up
Tip
In the document you just opened, the masters in the stencils
have colored backgrounds, unlike those in the previous graphics. This
is because the diagram for this exercise includes a theme.
-
Right-click the Start shape.
The right-click menu includes two BPMN entries at the top that
provide the “chameleon” features referred to the introduction to
this section. The Event Type entry lets you change the current shape
to any other event type. The Trigger/Result entry lets you select a
subtype for the Start event.
Each type of BPMN shape has its own set of right-click
menus.
-
With the right-click menu open, point to Trigger/Result, and then click Message. The start shape displays a white
envelope, indicating that a message triggers the launch of this
process.
-
Drag a Task shape from the
BPMN Basic Shapes stencil,
position it above the Seats
available? shape, and drop it on the connector labeled
No. The Visio 2010 AutoAdd feature
splits the connector and inserts the new shape.
-
With the new task still selected, type Offer alternate
seats, and then press Esc.
-
Drag a Gateway shape from
the BPMN Basic Shapes stencil,
position it above the Print
tickets shape, and drop it on the unlabeled
connector.
-
With the new gateway still selected, type Accept alternate
seats? and then press Esc.
-
Use the AutoConnect arrow
under the Accept alternate seats?
shape to draw a connector to the top of the Print tickets shape.
-
With the new connector still selected, type Yes.
-
Click once on the connector from the Accept alternate seats? shape to the End
shape, type No, and then press Esc.
To finish this exercise, you will mark each task with
a BPMN symbol to designate the task type.
-
Right-click the Check seat
inventory shape, point to Task
Type, and click User.
-
Right-click Offer alternate
seats, move to Task
Type, and click User.
-
With the Offer alternate
seats shape still selected, point to Loop, and click Standard.
A loop symbol appears in the task shape, indicating that this
task will be repeated until certain conditions are met. You will
describe those conditions with a text callout in the next
step.
-
Drag a Text Annotation
shape from the BPMN Basic Shapes
stencil, attach it to the Offer alternate
seats shape, and type Continue until customer accepts or rejects alternate
seats.
-
Right-click the Print
tickets shape, point to Task
Type, and click Service to indicate that this activity is
performed by a system.
-
Right-click the Send or hold
tickets shape, point to Task
Type, and click User.
There is also a
set of rules provided for validating BPMN diagrams. Many of the same
connectivity rules are included in the BPMN rule set; however,
because BPMN diagrams can be more complex, there are many additional
rules.
In the final step of this exercise, you will validate your
BPMN drawing.
-
On the Process tab, in the
Diagram Validation group, click
the Check Diagram button.
Visio displays a dialog box reporting “Diagram validation is
complete. No issues were found in the current document.”
Clean Up
Save your changes to the Theater
Ticketing Process drawing but leave it open if you are
continuing with the next exercise.
The ticketing process used in this exercise is deliberately very
simplistic. You could easily argue that more of the steps are automated
in most theater box offices and that there should be other tasks
involved. All of that is true, but the purpose of this exercise is to
learn a bit about BPMN and not to create the ultimate theater ticketing
process.
