Dealing with Changes of TimeAware Processes Andreas Lanz

Dealing with Changes of Time-Aware Processes Andreas Lanz, Manfred Reichert 11 -09 -2014 Image by www. sxc. hu, saavem

v 1. 0 Page 2 Dealing with Changes of Time-Aware Processes | Andreas Lanz, Manfred Reichert | 11 -09 -2014 Motivation • Time and temporal restrictions are omnipresent • Durations • Appointments • Deadlines • … • Time perspective raises fundamental challenges for any process-aware information system • Existing PAIS offer only a limited support for modeling and managing time-aware processes [Lanz et al. , 14]

v 1. 0 Page 3 Dealing with Changes of Time-Aware Processes | Andreas Lanz, Manfred Reichert | 11 -09 -2014 Motivation The Challenge: • Time can neither be slowed down nor stopped Time-aware processes need to be flexible to cope with unforeseen events or delays • Should be possible to dynamically adapt time-aware process instances • Re-schedule deadlines, dynamically modify temporal constraints • Structurally change a process instance “Lost time is never found again. ” – Benjamin Franklin (1706 -1790)

v 1. 0 Page 4 Dealing with Changes of Time-Aware Processes | Andreas Lanz, Manfred Reichert | 11 -09 -2014 Motivation Change operations for time-aware processes Control Flow Changes • • • Insert Activity Serially Insert Activity Parallel Insert Activity Conditionally • Delete Activity Temporal Constraint Changes • • Insert Time Lag Insert Fixed Date Element • • Delete Time Lag Delete Fixed Date Element • Temporal Consistency of the process instance needs to be ensured

v 1. 0 Page 5 Dealing with Changes of Time-Aware Processes | Andreas Lanz, Manfred Reichert | 11 -09 -2014 • Motivation Time-Aware Processes • Change Operations for Time-Aware Processes • Analyzing the Effects • Conclusion

v 1. 0 Page 6 Dealing with Changes of Time-Aware Processes | Andreas Lanz, Manfred Reichert | 11 -09 -2014 Time-aware Processes – Time Constraints* • Time Constraints • • • Activity Durations • Time Lags (min waiting time, max delay, …) A B Latest Finish Date • Fixed Date Elements (appointments, deadlines…) * [Lanz et al. , 14] A Minimum Maximum • • Start-Start-End End-Start End-End • • Earliest Start Latest Start Earliest Completion Latest Completion

v 1. 0 Page 7 Dealing with Changes of Time-Aware Processes | Andreas Lanz, Manfred Reichert | 11 -09 -2014 Modeling Time-Aware Processes • Important Question: Can an instance of the process model be completed without violating any time constraints? temporal consistency Solution: Conditional Simple Temporal Network (CSTN)* = Simple Temporal Network + Propositions * [Tsamardinos et al. , 03, Hunsberger et al. , 12]

v 1. 0 Page 8 Dealing with Changes of Time-Aware Processes | Andreas Lanz, Manfred Reichert | 11 -09 -2014 Conditional Simple Temporal Network* (CSTN) constraint Time Constraint time point A B proposition representing the execution path Consistency Check* • May restrict existing constraints • Derives interdependencies A * [Tsamardinos et al. , 03, Hunsberger et al. , 12] B

v 1. 0 Page 9 Dealing with Changes of Time-Aware Processes | Andreas Lanz, Manfred Reichert | 11 -09 -2014 CSTN Transformation* Activity AS AE XOR-Split true observation node X P? false Similar: XOR-Join, AND-Split, AND-Join * [Lanz et al. , 13] XS XE P?

v 1. 0 Page 10 Dealing with Changes of Time-Aware Processes | Andreas Lanz, Manfred Reichert | 11 -09 -2014 Modeling Time-Aware Processes – Minimal Network Process Model Minimal CSTN Time Model • Restricted constraints • Derived interdependencies • Constraint between any pair of time points

v 1. 0 Page 11 Dealing with Changes of Time-Aware Processes | Andreas Lanz, Manfred Reichert | 11 -09 -2014 Modeling Time-Aware Processes – Temporal Consistency Definition (Temporal Consistency). A time-aware process model is denoted as temporally consistent iff the corresponding time model (i. e. , its CSTN representation) is (weakly) consistent. it exists a minimal time model • Weak consistency of the CSTN can be check using the algorithm proposed by [Tsamardinos et al. , 03]

v 1. 0 Page 12 Dealing with Changes of Time-Aware Processes | Andreas Lanz, Manfred Reichert | 11 -09 -2014 Executing Time-Aware Processes • Time constraints need to be monitored during execution • Not sufficient to check consistency only at design time • Hidden interdependencies between time constraints may exist à May restrict explicit constraints à Need to be known when executing a process instance

v 1. 0 Page 13 Dealing with Changes of Time-Aware Processes | Andreas Lanz, Manfred Reichert | 11 -09 -2014 Executing Time-Aware Processes Creation of a new process instance Create a copy of the minimal time model Update instance time model to current state Updated activity execution times Execute process instance activities

v 1. 0 Page 14 Dealing with Changes of Time-Aware Processes | Andreas Lanz, Manfred Reichert | 11 -09 -2014 • Motivation • Time-Aware Processes Change Operations for Time-Aware Processes • Analyzing the Effects • Conclusion

v 1. 0 Page 15 Dealing with Changes of Time-Aware Processes | Andreas Lanz, Manfred Reichert | 11 -09 -2014 Change Operations – Basic Procedure Check applicability of change operation Update process model Update instance time model Restore minimality of instance time model Update hidden interdependencies

v 1. 0 Page 16 Dealing with Changes of Time-Aware Processes | Andreas Lanz, Manfred Reichert | 11 -09 -2014 Insert Activity Serially

v 1. 0 Page 17 Dealing with Changes of Time-Aware Processes | Andreas Lanz, Manfred Reichert | 11 -09 -2014 Insert Activity Conditionally

v 1. 0 Page 18 Dealing with Changes of Time-Aware Processes | Andreas Lanz, Manfred Reichert | 11 -09 -2014 Insert Time Lag

v 1. 0 Page 19 Dealing with Changes of Time-Aware Processes | Andreas Lanz, Manfred Reichert | 11 -09 -2014 Change Operations

v 1. 0 Page 20 Dealing with Changes of Time-Aware Processes | Andreas Lanz, Manfred Reichert | 11 -09 -2014 • Motivation • Time-Aware Processes • Change Operations for Time-Aware Processes Analyzing the Effects • Conclusion

v 1. 0 Page 21 Dealing with Changes of Time-Aware Processes | Andreas Lanz, Manfred Reichert | 11 -09 -2014 Applying multiple change operations Check applicability of change operation Update process model Update instance time model Approximate newofinstance Restore minimality instancetimemodel Update hidden interdependencies Restore minimality of instance time model Update hidden interdependencies

v 1. 0 Page 22 Dealing with Changes of Time-Aware Processes | Andreas Lanz, Manfred Reichert | 11 -09 -2014 Analyzing the Effects Proof in [Lanz et al. , 14 a]

v 1. 0 Page 23 Dealing with Changes of Time-Aware Processes | Andreas Lanz, Manfred Reichert | 11 -09 -2014 Example Theorem 1 – Insert Serial

v 1. 0 Page 24 Dealing with Changes of Time-Aware Processes | Andreas Lanz, Manfred Reichert | 11 -09 -2014 Multiple Change Operations – Optimized Procedure Restore minimality of instance time model Check applicability of change operation Update hidden interdependencies Update process model Update instance time model Approximate new instance time model Restore minimality of instance time model Update hidden interdependencies

v 1. 0 Page 25 Dealing with Changes of Time-Aware Processes | Andreas Lanz, Manfred Reichert | 11 -09 -2014 Applying Multiple Change Operations restore minimality

v 1. 0 Page 26 Dealing with Changes of Time-Aware Processes | Andreas Lanz, Manfred Reichert | 11 -09 -2014 Applying Multiple Change Operations • Approximate the resulting temporal properties of the entire process instance • Significantly reduces the complexity of applying multiple change operations • Actual saving depend on the “strictness” of the temporal constraints and the changes to be performed

v 1. 0 Page 27 Dealing with Changes of Time-Aware Processes | Andreas Lanz, Manfred Reichert | 11 -09 -2014 • Motivation • Time-Aware Processes • Change Operations for Time-Aware Processes • Analyzing the Effects Conclusion

v 1. 0 Page 28 Dealing with Changes of Time-Aware Processes | Andreas Lanz, Manfred Reichert | 11 -09 -2014 Summary • Time is a fundamental concept for business processes • Flexibility is important for time-aware processes • Change operations for time-aware processes instances • Approximation for applying multiple changes • Significantly reduces the complexity of applying multiple change operations • Proof-of-Concept implementation as part of the ATAPIS Toolset

v 1. 0 Page 29 Dealing with Changes of Time-Aware Processes | Andreas Lanz, Manfred Reichert | 11 -09 -2014 Ongoing and Future Work • Investigating more complex change patterns • Application of presented results to process evolution • Integration of advanced time-management capabilities into the ATAPIS Toolset Questions? dbis. info/atapis

v 1. 0 Page 30 Dealing with Changes of Time-Aware Processes | Andreas Lanz, Manfred Reichert | 11 -09 -2014 References [Hunsberger et al. , 12] Luke Hunsberger, Roberto Posenato, and Carlo Combi. The dynamic controllability of conditional STNs with uncertainty. In Proceedings of the Planning and Plan Execution for Real-World Systems: Principles and Practices (Plan. Ex), 2012. [Lanz et al. , 13] Andreas Lanz, Roberto Posenato, Carlo Combi, and Manfred Reichert. Controllability of time-aware processes at run time. In Proceedings of the 21 st International Conference on Cooperative Information Systems (Coop. IS'13), pages 39 --56. Springer, 2013. [Lanz et al. , 14] Andreas Lanz, Barbara Weber, and Manfred Reichert. Time patterns for processaware information systems. Requirements Engineering, 19(2): 113 -141, 2014. [Lanz et al. , 14 a] Andreas Lanz and Manfred Reichert. Process change operations for time-aware processes. Technical Report UIB-2014 -01, University of Ulm, 2014. [Tsamardinos et al. , 03] Ioannis Tsamardinos, Thierry Vidal, and Martha E. Pollack. CTP: A new constraint-based formalism for conditional, temporal planning. Constraints, 8(4): 365 --388, 2003.