Lezione 14 Model Transformations for BP Analysis and Execution

Transcription

1 Lezione 14 Model Transformations for BP Analysis and Execution Ingegneria dei Processi Aziendali Modulo 1 - Servizi Web Unità didattica 1 Protocolli Web Ernesto Damiani 1 Università di Milano 1

2 Business Process Management (BPM) Collection of methods and techniques to design, analyze, execute and monitor business operations involving humans, software, information and physical artifacts using process models. 2 2

3 OK, so what is a process model? Collection of inter-dependent activities whose collective performance is intended to achieve a goal such as delivering a product or a service. E,g. order-to-cash, procure-to-pay, issue-toresolution Obtain Additional Information Credit Card Application Check Completeness Check Credit History Assess Application Make Credit Offer Check Income Source(s) Notify Rejection 3 3

4 Process models serve many purposes Process Documentation Process Improvement Compliance / Risk Management Knowledge Management Enterprise Systems Process Cost Analysis / Simulation Workflow Management Document Management Software Evaluation/ Selection Enterprise Architecture 4 4

5 they have many faces Measures for Improvement Organizational Analysis AS IS Process Models Process Analysis & Design TO BE Process Models Abstract Models EPC, BPMN Communication, simulation, activitybased costing Process Evaluation Process Metrics Target Values Process Enactment & Monitoring Process Implementation Executable Process Models Detailed Models BPEL, State Machines Data types, conditions, data mappings, fault handling Integration, testing, deployment 5 5

6 and can be seen from many perspectives Control-flow Data Resource Operational V Temp picture cut Music cues Temp picture cut Dialog cues Effect cues Composer Music design V Temp music output Sound Designer Editor V Sound design V V V Temp sound output Dialog premix FX premix 6 6

7 Many in one, or one in many? The thing can be many in one sense, but also can be one in another sense. Imam Ghazali Revival of Religious Sciences 7 7

8 Process Modelling: Dealing with Multiplicity Multiple modelling languages (meta-models) Multiple modelling viewpoints Control-flow view vs. data view Public views (protocols) vs. private views Multiple abstraction levels High-level: tasks, performance metrics... Low-level: data transformations, application bindings

9 Process Modelling Notations Business Process Modelling Notation (BPMN) Event-driven Process Chains (EPC) Business Process Execution Language (BPEL) State machines and variants (e.g. IBM Business State Machine, WWF) Petri nets (and variants, e.g. YAWL) 9 9

10 Model transformations BPMN-to-BPEL Purpose: Transform models produced by analysts into models for developers (and vice-versa) Commonly supported in commercial tool, but in a limited manner BPEL-to-Petri nets For analysis & verification BPMN-to-Petri nets For analysis & verification (e.g. deadlockfreeness) 10 10

11 BPMN from miles Event Task Flow Gateway 11 11

12 BPMN: A more detailed view Start Event Intermediate Message Event Intermediate Timer Event End Event End Terminate Event Task Parallel Fork Gateway c receive ~c Flow Parallel Join Gateway Data-based Decision Gateway Event-based Decision Gateway Merge Gateway 12 12

13 Quick BPMN example Reject order Check stock availability Send invoice Confirm order Ship goods 13 13

14 BPEL from miles Basic activities: <assign>, <invoke>, <receive> Sequential flow: <sequence>, <while>, <switch> Block-structured parallel flow: <flow> Graph-oriented (parallel) flow: <link> ** Event-action rules: <onevent> ** Other constructs not relevant to this talk ** Only partially supported by some tools 14 14

15 A quick BPEL example 15 <sequence> <invoke check stock availability /> <switch ( ) /> <case reject > <invoke order rejection /> </case> <otherwise> <sequence> <invoke order acceptance /> <flow> <invoke invoicing /> <invoke ship goods /> </flow> </sequence> </otherwise> </switch> </sequence> 15

16 BPMN-to-BPEL: Some monsters! B A D A B C D C Bounded multipleinstance task (D) Unstructured loop A B C D A D Unbounded multipleinstance tasks (C) Livelock 16 16

17 BPMN-to-BPEL (from miles) Repeat until reduction to a single node 1. Identify a structured & quasi-structured SESE region Fold into a BPEL structured activity 2. Identify irreducible SESE regions without parallelism Apply Goto While transformations, repeat from 1 3. Identify acyclic fragments with concurrency Fold into a BPEL activity with control links 4. Identify minimal unstructured components BPEL event handlers 17 17

18 BPMN-BPEL: Structured Components C t1 e1 tn tc <sequence> <invoke name="t1"/> <receive name="e1"/>... <invoke name="tn"/> </sequence> ( a ) SEQUENCE-component C t1 e2 tc <flow> <invoke name="t1"/> <wait name="e2"/>... <invoke name="tn"/> </flow> tn ( b ) FLOW-component 18 18

19 BPMN-BPEL: Structured Components C t1 ~c1 c1 tc <while condition="c1"> <invoke name="t1"/> </while> ( e ) WHILE-component C t1 ~c1 tc c1 ( f ) REPEAT-component <sequence> <invoke name="t1"/> <while condition="c1"> <invoke name="t1"/> </while> </sequence> 19 19

20 BPMN-BPEL: Structured Components C c1 c2 default t1 e1 tc ( c ) SWITCH-component <switch> <case condition="c1"> <invoke name="t1"/> </case> <case condition="c2"> <receive name="e1"/> </case>... <otherwise> <empty/> </otherwise> </switch> C tr (receive) e1 e2 t1 tn tc <pick> <onmessage name="e1"/> <invoke name="t1"/> </onmessage> <onalarm name="e2"> <empty/> </onalarm>... <onmessage name="tr"> <invoke name="tn"/> </onmessage> </pick> ( d ) PICK-component 20 20

21 Example: Only Structured Components Sequence-component Switch-component Reject order Sequence-component Flow-component Check stock availability Send invoice Confirm order Ship goods 21 21

22 BPMN-to-BPEL: Acyclic component BPMN BPEL Flow-component T1 T3 T1 AND T3 T2 T4 T2 T4 Proposition: Every acyclic BPMN component with a single entry point and a single exit point that is 1-safe and sound can be mapped to a BPEL Flow with links 22 22

23 Example Structured+Acyclic Components UBL a 1 receive despatch-advice C1 f 2 f 3 a 2 receive invoice d 1 m 5 j 6 EDI receive EDI 856 (ASN) receive EDI 810 (Invoice) m 4 a 3 a 5 a 4 send payment-request a 6 send fulfillment-notice C2 a 6 tc 1 send fulfillment-notice tc

24 Minimizing the use of control links a1 g1 a2 fc a3 g3 a4 g2 a6 g5 a8 jc a5 g4 a7 t1 [a1, a2] fc t2 [a3, a4] t3 [a6, a8] jc a5 g4 a

25 For the rest Identify a minimal SESE region that is neither structured nor acyclic For each action in the component, retrieve: All actions that immediately precede it All actions that immediately follow it 25 For each action, code the following behaviour using event-action rules: Wait for a suitable combination of predecessors to complete Perform action Notify completion to all successors 25

26 BPEL-to-Petri net Application to Conformance Checking abstract BPEL process Conformance? Services Services Services Translation SOAP Messages Monitoring / Correlation Petri net model Conformance Checking! Event Log 26 26

27 From BPEL to WF-nets 27 27

28 Petri net-based Conformance Checking Objectives: quantitatively measure conformance locate deviations Conformance? 28 28

29 Conformance Checking Fitness 29 29

30 Conformance Checking Fitness 30 30

31 Measuring fitness: Log replay analysis missing tokens remaining tokens consumed tokens produced tokens =

32 Measuring fitness: Log replay analysis missing tokens remaining tokens consumed tokens produced tokens = 1 =

33 Measuring fitness: Log replay analysis missing tokens remaining tokens consumed tokens produced tokens = 2 =

34 Measuring fitness: Log replay analysis missing tokens remaining tokens consumed tokens produced tokens = 3 =

35 Measuring fitness: Log replay analysis missing tokens remaining tokens consumed tokens produced tokens = 5 =

36 Measuring fitness: Log replay analysis missing tokens remaining tokens consumed tokens produced tokens = 6 =

37 Measuring fitness: Log replay analysis missing tokens remaining tokens consumed tokens produced tokens = 7 =

38 Measuring fitness: Log replay analysis missing tokens remaining tokens consumed tokens produced tokens = 9 =

39 Measuring fitness: Log replay analysis missing tokens remaining tokens consumed tokens produced tokens = 9 =

40 Measuring fitness: Log replay analysis missing tokens remaining tokens consumed tokens produced tokens =

41 Measuring fitness: Log replay analysis missing tokens remaining tokens consumed tokens produced tokens = 1 =

42 Measuring fitness: Log replay analysis missing tokens remaining tokens = 1 consumed tokens produced tokens = 2 =

43 Measuring fitness: Log replay analysis missing tokens remaining tokens = 1 consumed tokens produced tokens = 3 =

44 Measuring fitness: Log replay analysis missing tokens remaining tokens = 1 consumed tokens produced tokens = 4 =

45 Measuring fitness: Log replay analysis missing tokens remaining tokens = 1 consumed tokens produced tokens = 6 =

46 Measuring fitness: Log replay analysis missing tokens remaining tokens = 1 consumed tokens produced tokens = 7 =

47 Measuring fitness: Log replay analysis missing tokens remaining tokens = 1 = 1 consumed tokens produced tokens = 8 =

48 Measuring fitness: Log replay analysis missing tokens remaining tokens = 1 = 1 consumed tokens produced tokens = 8 =

49 Measuring fitness: Log replay analysis 49 49

50 Measuring fitness: Log replay analysis f = 1.0 f f

51 Conformance Checking - Appropriateness 100 % fitness but not sufficiently specific from behavioral point of view. 100 % fitness but not represented in structurally suitable way

52 Ongoing work Reversible BPMN BPEL transformation Two-way transformation: BPEL FSM Application to automated service composition BPEL FSM not too difficult FSM BPEL more exciting, e.g. A B A B A B FINE 52 52