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92131562-Time Management Method(slides only)

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Pegah Hamidkhani
Pegah Hamidkhani

This document discusses time management methods in workflow management systems. It outlines 6 time constraints that can be applied to activities in a workflow model including time duration, forced start time, deadline, fixed date constraint, time difference, and time distance. It then describes how to calculate the critical path of a workflow both at build time and runtime by using forward and backward calculations while considering these time constraints. Finally, it discusses how identifying the critical path can benefit workflow designers and managers and provides solutions for handling potential time constraint violations.

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ATIME MANAGEMENT METHOD IN WORKFLOW MANAGEMENT SYSTEM Pegah Hamidkhani Mianji Student no: 92131562 In the name of God BPR Presentation Thought by: Dr. Alireza Hashemi
Intro Competition In Market Environment Change from Cost and Quality to Flexibility and Responsiveness Workflow management systems provides the foundation for defining and executing business Processes The time constraints and time management are very important
Overview In this Presentation will see: 6 time constraints in workflow modeling Workflow routing and Control Condition Calculate critical Path in build time Forward Calculation Backward Calculation Calculate critical Path in run time Forward Calculation Backward Calculation A solution for uncertainty of execution time Conclusion
Workflow Model A collection of activities and dependencies among activities Some Model definition Tools: Petri Nets , XPDL Here we use directed graph: N: Activity C: Edge The activity is denoted by: D: I/O Data E: executor R: resource T: time constraint In this presentation we focus on time constraints
Timed constraints Time Duration: The time span from the activity is inactive state to completed => Compulsory Forced start time: Is the time that an activity should be executed after it Deadline: Is a time that an activity be completed Fixed Date Constraint: An activity can only be executed on certain fixed dates. For example: every Monday left bound of constraint right bound of constraint
Timed constraints Time Difference: the time difference between two activities is caused by different time zones Time Distance: the time duration between activity A1 and A2, where A1 is the predecessor of A2 We show them like : The Value of each time constraint, if exist, is assigned by the workflow designer according to the experience value in build time.
Control Routing
Iteration Time Duration Probability of iteration: p Total average execution time: T A2 A4 A1 A3
Workflow Critical path We use extended Critical Path Method (CPM) with time constraints considered : earliest start time of an activity : earliest finish time of an activity : latest start time of an activity : latest finish time of an activity Depending on control dependencies between activities in workflow these are calculated
Rules In Critical Path Computation Assume A and B are two adjacent activities and A is the predecessor of B 乞 of B is 乞 of A plus the time duration of A If some time distance required the 乞 of B is: If they are in different time zones, the time difference must be taken into account If time zone B is in the working hours Or, time zone B is not in working hours
Rules In critical path computation If there is a fixed date constraint on activity B, we have two situations: If the time 乞 + is located in the space of the fix date else
Build Time Calculation Considerations Time constraints according to the experience or estimated value We treat all routing controls as AND-Split / AND-Join The forced start time, deadline and time difference cant be identified because workflow is static
Build Time Calculation (Forward)
Build Time Calculation (Backward)
Runtime Calculation Considerations Start time is real and the time information of all the other Activities can be Identified All six time constraints should be taken into account All OR-Split/ OR-Join pair will be checked So a new graph is given for calculation ゐ (for time difference constraint) and ゐ (for fixed date constraint) can be figured out exactly
Runtime Calculation (Forward)
Runtime Calculation (Forward)
Runtime Calculation (Backward)
Runtime Calculation (Backward)
Benefits Of Time Management After Identifying the critical path of a workflow process we can benefit from it Workflow designers: Find bottlenecks and try to optimize the process Find any potential time constraint conflict and resolve error Workflow managers: Adjust the time plan according to time constraints Schedule the activities in the work in the work list to enhance the throughput Monitor the execution and be alerted about potential time error Adjust the execution of workflow instance if any time constraint is violated
Time Constraint Violation Deadline violation: the activity cant be complete before its deadline Four methods to overcome Adjust the time durations of activities that are under scheduling Try to postpone the deadline of the very activity that will be violated Try to find another path to replace current path If the former 3 methods cant work the system will arouse time exception and use exception handling Forced start time error: system has to wait for certain time
Uncertainty of execution Time We previously used experience or previous estimation but this approach is very static Estimate at process instantiation based on Executer Instance Try to calculate the time extracted from history data or logs of existing WFMSs If no log exist get the time from who take charge of the related job l=
Conclusion We defined 6-tuple time constraints, to ensure that the business process can be executed properly The algorithm of identifying the critical path of certain workflow process is given based on 6 time constraints Benefits of time management described How to face time constraint violation
Refrence Weiping Li ; Sch. of Software & Microelectronic, Peking Univ., Beijing ; Yushun Fan (2009) A Time Management Method in Workflow Management System, Grid and Pervasive Computing Conference.
92131562-Time Management Method(slides only)

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92131562-Time Management Method(slides only)

  • 1. ATIME MANAGEMENT METHOD IN WORKFLOW MANAGEMENT SYSTEM Pegah Hamidkhani Mianji Student no: 92131562 In the name of God BPR Presentation Thought by: Dr. Alireza Hashemi
  • 2. Intro Competition In Market Environment Change from Cost and Quality to Flexibility and Responsiveness Workflow management systems provides the foundation for defining and executing business Processes The time constraints and time management are very important
  • 3. Overview In this Presentation will see: 6 time constraints in workflow modeling Workflow routing and Control Condition Calculate critical Path in build time Forward Calculation Backward Calculation Calculate critical Path in run time Forward Calculation Backward Calculation A solution for uncertainty of execution time Conclusion
  • 4. Workflow Model A collection of activities and dependencies among activities Some Model definition Tools: Petri Nets , XPDL Here we use directed graph: N: Activity C: Edge The activity is denoted by: D: I/O Data E: executor R: resource T: time constraint In this presentation we focus on time constraints
  • 5. Timed constraints Time Duration: The time span from the activity is inactive state to completed => Compulsory Forced start time: Is the time that an activity should be executed after it Deadline: Is a time that an activity be completed Fixed Date Constraint: An activity can only be executed on certain fixed dates. For example: every Monday left bound of constraint right bound of constraint
  • 6. Timed constraints Time Difference: the time difference between two activities is caused by different time zones Time Distance: the time duration between activity A1 and A2, where A1 is the predecessor of A2 We show them like : The Value of each time constraint, if exist, is assigned by the workflow designer according to the experience value in build time.
  • 8. Iteration Time Duration Probability of iteration: p Total average execution time: T A2 A4 A1 A3
  • 9. Workflow Critical path We use extended Critical Path Method (CPM) with time constraints considered : earliest start time of an activity : earliest finish time of an activity : latest start time of an activity : latest finish time of an activity Depending on control dependencies between activities in workflow these are calculated
  • 10. Rules In Critical Path Computation Assume A and B are two adjacent activities and A is the predecessor of B 乞 of B is 乞 of A plus the time duration of A If some time distance required the 乞 of B is: If they are in different time zones, the time difference must be taken into account If time zone B is in the working hours Or, time zone B is not in working hours
  • 11. Rules In critical path computation If there is a fixed date constraint on activity B, we have two situations: If the time 乞 + is located in the space of the fix date else
  • 12. Build Time Calculation Considerations Time constraints according to the experience or estimated value We treat all routing controls as AND-Split / AND-Join The forced start time, deadline and time difference cant be identified because workflow is static
  • 15. Runtime Calculation Considerations Start time is real and the time information of all the other Activities can be Identified All six time constraints should be taken into account All OR-Split/ OR-Join pair will be checked So a new graph is given for calculation ゐ (for time difference constraint) and ゐ (for fixed date constraint) can be figured out exactly
  • 20. Benefits Of Time Management After Identifying the critical path of a workflow process we can benefit from it Workflow designers: Find bottlenecks and try to optimize the process Find any potential time constraint conflict and resolve error Workflow managers: Adjust the time plan according to time constraints Schedule the activities in the work in the work list to enhance the throughput Monitor the execution and be alerted about potential time error Adjust the execution of workflow instance if any time constraint is violated
  • 21. Time Constraint Violation Deadline violation: the activity cant be complete before its deadline Four methods to overcome Adjust the time durations of activities that are under scheduling Try to postpone the deadline of the very activity that will be violated Try to find another path to replace current path If the former 3 methods cant work the system will arouse time exception and use exception handling Forced start time error: system has to wait for certain time
  • 22. Uncertainty of execution Time We previously used experience or previous estimation but this approach is very static Estimate at process instantiation based on Executer Instance Try to calculate the time extracted from history data or logs of existing WFMSs If no log exist get the time from who take charge of the related job l=
  • 23. Conclusion We defined 6-tuple time constraints, to ensure that the business process can be executed properly The algorithm of identifying the critical path of certain workflow process is given based on 6 time constraints Benefits of time management described How to face time constraint violation
  • 24. Refrence Weiping Li ; Sch. of Software & Microelectronic, Peking Univ., Beijing ; Yushun Fan (2009) A Time Management Method in Workflow Management System, Grid and Pervasive Computing Conference.