Presentation about jBPM - business process framework from JBoss

1. &
jBPM & BPMN
jPrase
Vít Kotačka
24. 11. 2011
© Adastra Group

2. Agenda
 BPMN
̶ Overview
 jBPM
̶ JBoss Middleware & BRMS
̶ Core Engine API
̶ Process Nodes
̶ Human Tasks
̶ Testing & debugging
2

3. BPMN Overview
3

4. Business Process Model and Notation
 Graphical representation for specifying business processes.
 Providing a notation that is intuitive to business users :-)
 Maintained by OMG (Object Management Group).
 Similar to Activity Diagrams from UML.
 Provides a mapping between
the graphics of the notation
and the underlying constructs
of execution languages (BPEL).
 Shows the flow of data (messages),
but it is not a data flow diagram.
4

5. Example Diagram
Business Process BPMN
Activity2
FirstLine
Activity1
StartEvent1 EndEvent1
Activity3
SecondLine
Activity4
Use Case1
(from Use Case)
5

6. Elements
 Flow objects
̶ Activity
̶ Event
̶ Gateway
 Connecting object
̶ Sequence flow
̶ Message flow
̶ Association
 Swim lanes
̶ Pool
̶ Lane
 Artifacts
̶ Data object
̶ Group
6

7. Activities
7

8. Events
 Start Event
 Stop Event
 Intermediate Event
̶ Interrupting
̶ Non-interrupting
8

9. Gateways
9

10. Swimlines
10

11. 72 Implementations
11

12. JBoss Middleware & BRMS
12

13. JBoss Enterprise Middleware
13

14. JBoss Enterprise SOA
14

15. Drools/JBoss BRMS
 Drools Guvnor: A centralised repository for Drools
Knowledge Bases. The repository component is
where you can store versions of rules, models,
functions, processes etc.
 Drools Expert: A forward chaining rule engine based
on Rete algorithm.
 jBPM: A light-weight, extensible workflow engine
written in pure Java that allows to execute business
processes using the latest BPMN 2.0 specification.
15

16. Core Engine API
16

17. Core Engine
17

18. Knowledge Base
 Contains a reference to all the relevant process definitions.
 Can be shared across sessions.
 Usually is only created once (at the start of the application).
 Can be dynamically changed (add/remove process at runtime).
KnowledgeBuilder kBuilder =
KnowledgeBuilderFactory
.newKnowledgeBuilder();
kBuilder.add(ResourceFactory
.newClassPathResource("hello.bpmn"),
ResourceType.BPMN2);
KnowledgeBase kBase =
kBuilder.newKnowledgeBase();
18

19. Session
 Can be created based on a knowledge base.
 Are used to execute processes and interact with engine.
 Multiple sessions can be created (independency, scalability).
 Is relatively lightweight.
StatefulKnowledgeSession session =
kBase.newStatefulKnowledgeSession();
ProcessInstance process =
session.startProcess(
"com.adastracorp.jbpm.hello");
19

20. Events
 Session can register listeners.
 ProcessEventListener listens to process-related events.
 KnowledgeRuntimeLoggerFactory adds logger to session.
̶ console logger
̶ file logger
20

21. ProcessEventListener
21

22. Process Nodes
22

23. Process Node Types
 Events: They are used to model the occurrence of a particular
event.
 Activities: These define the different actions that need to be
performed during the execution of the process.
 Gateways: Can be used to define multiple paths in the
process.
23

24. Events
 Start Event: The start of the process.
 End Events
̶ End Event: The end of the process.
̶ Throwing Error Event: Can be used to signal
an exceptional condition in the process.
 Intermediate Events
̶ Catching Timer Event: A timer that can trigger
one or multiple times after a given period of
time.
̶ Catching Signal Event: Can be used to
respond to internal or external events during
the execution of the process.
24

25. Gateways
 Diverging Gateway
̶ AND (parallel)
̶ XOR (exclusive)
̶ OR (inclusive)
 Converging Gateway
̶ AND
̶ XOR
25

26. Activities
 Script Task: A script that should be executed in this
process. Can access any variables and globals.
 Service Task: An (abstract) unit of work that should
be executed in this process (work that is executed
outside the process engine).
 User Task: An (atomic) task that need to be
executed by human actors.
 Reusable Sub-process: An invocation of another
process from within this process.
 Business Rule Task: A set of rules that need to be
evaluated. Rules are defined in separate files using
the Drools rule format.
26

27. Activities
 Embedded Sub-process: A Sub-
Process is a node that can contain
other nodes so that it acts as a node
container. If you use a terminating
event node inside a sub-process, you
are terminating the top-level process
instance, not just that sub-process.
 Mulit-instance Sub-process: Allows you
to execute the contained process
segment multiple times, once for each
element in a collection.
27

28. Human Tasks
28

29. Human Tasks
 Based on the WS-HumanTask specification.
 An atomic task that needs to be executed by a human actor.
 Can be assigned to
̶ one specific user
̶ one or more groups
 Can be used in combination with swimlanes to assign multiple
human tasks to the same actor.
 Human task service
̶ manages the life cycle of the tasks (creation, claiming, completion, etc.)
̶ stores the state of all the tasks
̶ supports features like internationalization, calendar integration, different
types of assignments, delegation, deadlines, etc.
29

30. Human Task Model
30

31. Human Task Life-cycle
31

32. Testing & debugging
32

33. Debugging
 Process Instance(s) View shows the currently running process
instances.
 Human Task View can connect to a running human task
service and request the relevant tasks for a particular user.
 Audit View is a log of all events that were logged from the
session.
33

34. What has been omitted
 Rule Tasks
 Persistence
 Transactions
 Domain-specific processes
 Process (Knowledge) repository
 Business Activity Monitoring
 Flexible Processes
34

35. Sources
 http://www.bpmn.org/
 http://www.bpmb.de/images/BPMN2_0_Poster_EN.pdf
 http://www.jboss.org/jbpm
35

36. 36