Business Process Modelling-using BPMN, part II

Prof. Alistair BarrosQueensland University of Technology

INB/N 205 Enterprise ArchitectureLecture 9

21 September 2011, Brisbane

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Orchestration Diagram Example

Business Process Model and Notation, Page 47OMG Document Number: formal/2011-01-03

January 2011

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Process (or Orchestration) Diagram

Models a participant and can be:

– Public (or Abstract) view (black box)

– Private view (white box)

Auc

tioni

ng S

ervi

ceA

uctio

ning

Ser

vice

Send auction creation

confirmationAuctionbegins

Send auction creation

confirmation

Conduct auction

Send auction completion notification

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Collaboration Diagram

Models a global business process between at least two participants (each modelled by a Pool). Before known as Business Process Diagram (BPD).

Sel

ler

Auc

tioni

ng S

ervi

ce

Auctioncreationrequest

Auctioncreation

confirmationPaymentdetails

Deliveryacknowledgement

Paymentacknowledgement

Bid

der

Auctioncompletionnotification

Auctioncompletionnotification

Send auction creation request

Send payment details

Send payment ack.

Send delivery notification

Goodssent

notification

Send auction creation

confirmationAuctionbegins

Send auction creation

confirmation

Conduct auction

Send auction completion notification

Bidacknowledgement

Bid

Publicprocess

Private process

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Collaboration Diagram Example

5

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Partner View

6

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BPMN 2.0 model types

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Issues with Inter-Connecting Partner Processes

8

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Enter Choreography

How is the interaction between multiple participants conducted!• Focus on message exchange between process steps and

participants• Choreography diagrams visualise ways of interactions• Sequence definition of participant interactions• Generally stand-alone diagrams (suited to be integrated

into collaboration diagrams)

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Choreography Diagram

Focuses on the interactions among two or more participants.

Order

Order Cancelation

Cancelation Ack

Order Confirmation Payment

Invoice

Cus

tom

erM

anuf

actu

rer

Requestfor Quote

Quote

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Choreography Diagram

Cancel Order

Order

Place OrderGet Quote

Confirm Order

Order Cancelation

Cancelation Ack

Order Confirmation Payment

Pay for Order

Invoice

Cus

tom

erM

anuf

actu

rer

Requestfor Quote

Quote

Interactions can be explicitly captured

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Choreography Diagram (cont’d)

Cancel Order

Customer

ManufactuerOrder

Place Order

Manufacturer

Customer

Requestfor Quote

Quote

Get Quote

Manufacturer

Customer

Confirm Order

Customer

Manufactuer

Order Cancelation

Cancelation Ack

Order Confirmation Payment

Pay for Order

Manufacturer

Customer

Invoice

Pools can be dropped

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Choreography Task

• Anatomic activity• Represents interaction between two process participants• Either one-way or two-way Chor. Task• Distinction between initiating and receiving participant• What are participants?

Participant

Initiating Participant

Choreography Task Name

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Choreography Task

• Band of initiating participant unfilled• Tethered message icons optional Choreography Task Collaboration View

Garage

Customer

Estimate of costs

Car

Cost estimate

Cus

tom

erHandover car Evaluate cost

estimationG

arag

e

Evaluate damage

CarCost estimate

...

...

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Basic Choreography Elements

Sequence flow – Connects and orders choreography tasks, events and gateways

Events – Most process events allowed. No non-interrupting events

Gateways – All process gateways allowed: Exclusive, Inclusive, Parallel and Event-based gateways

AnnotationText annotations, groups – No restrictions on their use

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Choreography Example

Business Process Model and Notation, Page 317OMG Document Number: formal/2011-01-03

January 2011

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ChoreographySequencing Constraints

The initiator of an Choreography Activity must have been involved in the previous Activity (excluding first activity)

Why?!

Business Process Model and Notation, Page 338OMG Document Number: formal/2011-01-03

January 2011

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ChoreographySequencing Constraints

Business Process Model and Notation, Page 339

OMG Document Number: formal/2011-01-03

January 2011

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Choreography of an auction - Example

A seller sends information about an item he wants to sell to an auction provider. The provider publishes the auction. When the auction starts bidder may place offers. In case the item is sold the auction provider finalises the purchase with the buyer, otherwise the seller will be notified about that his item has not been sold.

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Choreography of an auction - Solution

Auction Provider

Seller

Compile auction

Auction Provider

Bidder

Place offer

Auction Provider

Buyer

Finalize purchase

Auction Provider

Seller

Notify of unsold item

Item sold

Item not sold

Auction Provider

Bidder

Offer item

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Choreography Task – Internal Markers

Only one of the loop, parallel- and sequential-multiple instance applicable

Loop Parallel Sequential

Participant B

Participant A

Choreography Task

Parti

cipa

nt A

Send Message

Parti

cipa

nt B

Receive Message

Participant B

Participant A

Choreography Task

Parti

cipa

nt A

Send MessagePa

rtici

pant

B

Receive Message

Participant B

Participant A

Choreography Task

Parti

cipa

nt A

Send Message

Parti

cipa

nt B

Receive Message

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Choreography Task – Internal Markers

Which of the internal markers could be applied in the auction example?

Auction Provider

Seller

Compile auction

Auction Provider

Bidder

Place offer

Auction Provider

Buyer

Finalize purchase

Auction Provider

Seller

Notify of unsold item

Item sold

Item not sold

Auction Provider

Bidder

Offer item

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Choreography Task: Multiple Participants

• Participants may be multiple instance participants• E.g. customers or shippers

Participant B

Participant A

Choreography Task

Par

ticip

ant A

Send Message

Par

ticip

ant B

Receive Message

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Sub-Choreography

• Compound activity of a choreography• Involves at least two participants• Loop, parallel and sequential MI and multiple participant

markers are applicable

Participant B

Participant A

Participant C

Choreography Sub-Process Name

Participant B

Participant A

Participant C

Choreography Sub-Process Name

Participant B

Participant C

Choreography Task Name A

Participant C

Participant A

Choreography Task Name B

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Sub-Choreography

Where in the auction example would a Sub-Choreography make sense? And why?

Auction Provider

Seller

Compile auction

Auction Provider

Bidder

Place offer

Auction Provider

Buyer

Finalize purchase

Auction Provider

Seller

Notify of unsold item

Item sold

Item not sold

Auction Provider

Bidder

Offer item

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More complex Choreography

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4 BPMN 2.0 model types

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Conversation

Who is interacting with whom!

• Bird’s eye perspective on complex interactions• Conversation diagrams

– contain multiple or all participants– display the interaction between participants

• Composition of multiple choreographies

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Conversation Diagram

Simplified view of a Collaboration diagram:

CustomerManufacturer Order negotiations

Request for QuoteQuote

Order

Order Cancelation

Cancelation Act

Order Confirmation

Invoice

Payment

CustomerManufacturer

Participant: a collapsed Pool

Conversation: logical grouping of related message exchanges

Link: connects Communications with Participants

Collapsed

Expanded

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Conversation: a more complex example...

Sub-Conversation: indicates a compound Conversation element

MI Participant: a set of participants of the same

kind

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Conversation Diagram Example

Business Process Model and Notation, Page 126OMG Document Number: formal/2011-01-03

January 2011

Issue in BPMN 2.0 Conversation Diagrams: How do we view (correlation) relationships between conversations?

So where is the difference between Conversation diagrams to Collaboration and Choreography diagrams?

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Conversation

Convert the auction example into a conversation

Auction Provider

Seller

Compile auction

Auction Provider

Bidder

Place offer

Auction Provider

Buyer

Finalize purchase

Auction Provider

Seller

Notify of unsold item

Item sold

Item not sold

Auction Provider

Bidder

Offer item

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Conversation - Solution

Convert the auction example into a conversation

Auction Provider

Seller Bidder Buyer

BiddingItem Compilation/Status

Item Purchase

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Collaboration Diagram Example

Business Process Model and Notation, Page 133OMG Document Number: formal/2011-01-03

January 2011

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References

Recommended• OMG (2011): BPMN 2.0 Specification• BPM Offensive (2011): BPMN 2.0 Poster• OGM (2010): BPMN 2.0 By Example• White S.: Introduction to BPMN 1.0• Recker J. et al. (2008): An Exploratory Study of Process Modeling Practice with BPMN

Web References• OMG BPM Initiative• BPMN Community

Books on BPMN• Silver B. (2009): BPMN Method & Style, Cody-Cassidy• White S., Miers D. (2008): BPMN Modeling and Reference Guide, Future Strategies• Grosskopf A., Decker G., Weske M. (2009): The Process: Business Process Modeling

using BPMN, Meghan-Kiffer Press