Object-Business Process Mapping Frameworks: Abstractions, Architecture, and Implementation (EDOC 2014)

The integration between enterprise architectures and Business Process Management Systems (BPMS) is currently based on low-level programming interfaces that expose accidental complexities typical of process implementations. This paper describes an approach for integrating software architectures and BPMSs, based on mapping frameworks. Our inspiration are the Object-Relational Mapping (ORM) frameworks widely used to shield information systems from low-level structures exposed by relational database systems. The paper describes the central abstractions that should be provided by Object–Business Process Mapping Frameworks (OBPM). We also propose a reference architecture for implementing OBPMs and a concrete OBPM implementation, called NextFlow. We evaluated our approach by comparing two implementations of the same system, one using NextFlow and another using the native API supported by jBPM, a popular BPMS. By using NextFlow, we achieved a reduction of 30% in terms of lines of code, 35% in terms of number of classes, and 90% in terms of import statements, when implementing this system.

Transcript

1. Object–Business Process
   Mapping Frameworks:
   Abstractions, Architecture, and
   Implementation
   Rógel Garcia de Oliveira
   Marco Túlio Valente
   {rogelgarcia,mtov}@dcc.ufmg.br
   APPLIED SOFTWARE ENGINEERING
   RESEARCH GROUP
   

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2. 1. Overview
   2. Abstractions
   3. Architecture
   4. Implementation
   5. Evaluation
   6. Conclusion
   Agenda
   EDOC, 2014 2
   

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3. 1. Overview
   

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4. Information
   System
   BPMS
   Overview
   • Proprietary library. Lock in
   BPMS tool.
   • API expose low-level
   abstractions.
   • High learning curve.
   Challenges
   EDOC, 2014 4
   

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5. void createProcessAndExecuteTask() {
   StatefulKnowledgeSession ks = createJbpmSession(" loanprocess . jbpm ");
   WorkflowProcessInstance pi = (WorkflowProcessInstance) ks.startProcess("process");
   WorkItemNodeInstance wi = getWorkItem(pi, "approve transaction");
   TransactionInfo ti = executeApproveTransaction(ks, wi, 1000);
   }
   WorkItemNodeInstance getWorkItem(WorkflowProcessInstance pi, String nodeName) {
   for (NodeInstance nodeInstance : pi.getNodeInstances())
   if (nodeInstance.getNode().getName().equals(nodeName))
   return (WorkItemNodeInstance) nodeInstance;
   return null;
   }
   TransactionInfo executeApproveTransaction(StatefulKnowledgeSession kSession,
   WorkItemNodeInstance wi, int value) {
   TransactionInfo ti = Application.approveTransaction(value);
   Map results = new HashMap();
   results.put("transactionInfo", ti);
   kSession.getWorkItemManager().completeWorkItem(wi.getNodeId(), results);
   return ti;
   }
   Example – jBPM API
   EDOC, 2014 5
   

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6. Proposed Solution
   Information
   System
   BPMS
   Object-Business
   Process Mapping
   Analogous to
   ORM
   (e. g. Hibernate)
   EDOC, 2014 6
   

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7. Objectives
   • Standard integration to various BPMSs
   • Decouple IS from proprietary BPMS
   APIs
   • Reduce accidental complexity
   EDOC, 2014 7
   

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8. 2. Abstractions
   

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9. Lifecycle
   Information
   System
   BPMS
   Object-Business
   Process Mapping
   1 – Build the process
   2 – Create the mapped interface
   3 – Calls are
   intercepted and
   delegated to the BPMS
   EDOC, 2014 9
   

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10. Lifecycle
    Information
    System
    BPMS
    4 –Data is syncronized
    Object-Business
    Process Mapping
    Object-Business
    Process Mapping
    EDOC, 2014 10
    

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11. Lifecycle
    Information
    System
    BPMS
    5 – When a taks is executed, callbacks
    may be triggered in the information
    system
    Object-Business
    Process Mapping
    EDOC, 2014 11
    

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12. Lifecycle
    Information
    System
    BPMS
    Object-Business
    Process Mapping
    EDOC, 2014 12
    

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13. Modeling Business Processes with OO
    • Process
    – ID: bankLoanProcess
    EDOC, 2014 13
    

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14. Mapped Interface
    @Process("bankLoanProcess")
    interface BankProcess {
    void approveTransaction();
    }
    EDOC, 2014 14
    

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15. Mapped Interface
    • Reveals process semantics
    • Accidental complexity is reduced
    • Independency of BPMS
    bankProcess.approveTransaction();
    EDOC, 2014 15
    

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16. Data
    • A process can have associated data
    – Process Dataset
    • Key-Value pairs
    – Process Attribute
    • Bank Loan Process
    – clientID Key Value
    clientID 456d
    EDOC, 2014 16
    

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17. Process Dataset
    @Process("bankLoanProcess")
    interface BankProcess {
    void approveTransaction();
    LoanData getLoanData();
    }
    class LoanData {
    String clientID; //getter and setter omitted
    }
    bankProcess.getLoanData().getClientID();
    EDOC, 2014 17
    

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18. Callback
    • Allows BPMS to execute services in the
    Information System
    – Complementary to Mapped Interfaces
    • Tasks are represented by methods
    EDOC, 2014 18
    

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19. Callback Class
    @Process("bankLoanProcess")
    class BankProcessCallback {
    void approveTransaction() {
    //extra behavior
    }
    }
    EDOC, 2014 19
    

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20. Callback Class – Data access
    @Process("bankLoanProcess")
    class BankProcessCallback {
    LoanData loanData;
    void approveTransaction() {
    //extra behavior
    }
    }
    EDOC, 2014 20
    

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21. 3. Architecture
    

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22. Architecture
    BPMS
    Workflow Connectivity
    Information System
    Object-Workflow Mapping
    EDOC, 2014 22
    

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23. Workflow Connectivity – SPI
    BPMS X
    WFC API
    WFC Client
    DRIVER X
    String url = "jwfc:bpmsX:processFiles“;
    Session s = WorkflowManager.connect(url);
    String p = getProtocol(url); // bpmsX
    Driver driver = getDriver(p);
    Session s = driver.connect(url);
    class DriverX implements Driver {
    String getProtocol(){return “bpmsX";}
    SessionX connect(String url){....}
    }
    EDOC, 2014 23
    

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24. Workflow Object Mapping
    Information
    System
    maps
    BPMS
    delegates
    Workflow
    Connectivity
    uses
    Object-Workflow
    Mapping
    provides
    EDOC, 2014 24
    

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25. Workflow Object Mapping
    @Process("bankLoanProcess")
    interface BankProcess {
    void approveTransaction();
    }
    class BankProcessImpl$$ implements BankProcess {
    ProcessInstance pi;
    void approveTransaction() {
    pi.getActivityByName("approveTransaction")
    .complete();
    }
    }
    EDOC, 2014 25
    

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26. Workflow Object Mapping
    @Process("bankLoanProcess")
    interface BankProcess {
    void approveTransaction();
    }
    class BankProcessImpl$$ implements BankProcess {
    ProcessInstance pi;
    void approveTransaction() {
    pi.getActivityByName("approveTransaction")
    .complete();
    }
    }
    EDOC, 2014 26
    

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27. 4. Implementation
    NextFlow
    

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28. Example
    Configuration conf =
    new Configuration("jwfc:bpmsX:resources");
    EDOC, 2014 28
    

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29. Example
    Configuration conf =
    new Configuration("jwfc:bpmsX:resources");
    conf.addCallbackClass(BankProcessCallback.class);
    EDOC, 2014 29
    

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30. Example
    Configuration conf =
    new Configuration("jwfc:bpmsX:resources");
    conf.addCallbackClass(BankProcessCallback.class);
    WorkflowObjectFactory factory = conf.createFactory();
    EDOC, 2014 30
    

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31. Example
    Configuration conf =
    new Configuration("jwfc:bpmsX:resources");
    conf.addCallbackClass(BankProcessCallback.class);
    WorkflowObjectFactory factory = conf.createFactory();
    BankProcess bp = factory.start(BankProcess.class);
    EDOC, 2014 31
    

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32. Example
    Configuration conf =
    new Configuration("jwfc:bpmsX:resources");
    conf.addCallbackClass(BankProcessCallback.class);
    WorkflowObjectFactory factory = conf.createFactory();
    BankProcess bp = factory.start(BankProcess.class);
    bp.approveTransaction();
    EDOC, 2014 32
    

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33. 4. Evaluation
    

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34. Charging System
    • Credit transfer system
    • Two implementations
    – jBPM (native library)
    – NextFlow (with jBPM driver)
    EDOC, 2014 34
    

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35. Charging System
    EDOC, 2014 35
    

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36. Starting a new process
    jBPM API
    StatefulKnowledgeSession kSession = ...;
    Map params = new HashMap();
    params.put("manager", (JbpmPhoneProcessManager) this);
    ProcessInstance p = kSession.startProcess(PROCESS_ID, params);
    NextFlow
    WorkflowObjectFactory factory = ...;
    ChargingProcess p = factory.start(ChargingProcess.class);
    EDOC, 2014 36
    

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37. Data manipulation
    jBPM API
    WorkflowProcessInstance process = node.getProcessInstance();
    Integer value = (Integer) process.getVariable("value");
    String to = (String) process.getVariable("to");
    Integer credit = chargingManager.getCreditFor(to);
    boolean enoughCredit = credit >= value;
    process.setVariable("enoughCredit", enoughCredit);
    NextFlow
    Integer credit = chargingManager.getCreditFor(data.getTo());
    data.setEnoughtCredit(credit >= data.getValue());
    EDOC, 2014 37
    

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38. Metrics
    NextFlow
    • LOC: 330 (-30%)
    • Classes/Interfaces: 11 (-35%)
    • Char Count: 12.921 (-50%)
    • API Imports: 6 (-90%)
    jBPM API
    • LOC: 475
    • Classes/Interfaces: 17
    • Char Count: 25.500
    • API Imports: 63
    EDOC, 2014 38
    

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39. 5. Conclusion
    

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40. Object-Business Process Mapping
    Framework
    • Less programming effort
    • Independency of BPMS
    • Reduction in accidental complexity
    • Process semantics is exposed
    EDOC, 2014 40
    

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41. QUESTIONS?
    DANKE SCHÖN!
    www.nextflow.org
    

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