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

Motivation Time and temporal restrictions are omnipresent Durations 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]

Motivation The Challenge: Time can neither be slowed down nor stopped 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)

Temporal Constraint Changes Dealing with Changes of Time-Aware Processes | Andreas Lanz, Manfred Reichert | 11-09-2014 Motivation Change operations for time-aware processes Temporal Consistency of the process instance needs to be ensured 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

Time-Aware Processes Motivation Dealing with Changes of Time-Aware Processes | Andreas Lanz, Manfred Reichert | 11-09-2014 Time-Aware Processes Motivation Change Operations for Time-Aware Processes Analyzing the Effects Conclusion

Time-aware Processes – Time Constraints* 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, …) Fixed Date Elements (appointments, deadlines…) A 𝑚𝑖𝑛𝐷, 𝑚𝑎𝑥𝐷 Minimum Maximum A B 𝑆 𝑚𝑖𝑛𝐷,𝑚𝑎𝑥𝐷 𝐸 Start-Start Start-End End-Start End-End Latest Finish Date A Earliest Start Latest Start Earliest Completion Latest Completion * [Lanz et al., 14]

Modeling Time-Aware Processes 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]

Conditional Simple Temporal Network* (CSTN) Dealing with Changes of Time-Aware Processes | Andreas Lanz, Manfred Reichert | 11-09-2014 Conditional Simple Temporal Network* (CSTN) Time Constraint constraint time point A B 𝑥,𝑦 ,𝛽 𝑥≤𝐵−𝐴≤𝑦 =𝐵−𝐴∈[𝑥,𝑦] proposition representing the execution path Consistency Check* May restrict existing constraints Derives interdependencies A B 𝑥 ′ , 𝑦 ′ , 𝛽 𝑦 ′ ≤𝑦 𝑥′≥𝑥 𝑥′≤𝐵−𝐴≤𝑦′ * [Tsamardinos et al., 03, Hunsberger et al., 12]

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

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

Modeling Time-Aware Processes – Temporal Consistency Dealing with Changes of Time-Aware Processes | Andreas Lanz, Manfred Reichert | 11-09-2014 Modeling Time-Aware Processes – Temporal Consistency  it exists a minimal time model Weak consistency of the CSTN can be check using the algorithm proposed by [Tsamardinos et al., 03] 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.

Executing Time-Aware Processes 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 May restrict explicit constraints Need to be known when executing a process instance

Executing Time-Aware Processes 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

Change Operations for Time-Aware Processes 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

Change Operations – Basic Procedure 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

Insert Activity Serially Dealing with Changes of Time-Aware Processes | Andreas Lanz, Manfred Reichert | 11-09-2014 Insert Activity Serially 𝒄 𝒎𝒂𝒙 ≥ 𝒅 𝒎𝒊𝒏 < 𝑚𝑎𝑥 𝑐 𝑚𝑖𝑛 , 𝑑 𝑚𝑖𝑛 , 𝑐 𝑚𝑎𝑥 ,𝛽>

Insert Activity Conditionally Dealing with Changes of Time-Aware Processes | Andreas Lanz, Manfred Reichert | 11-09-2014 Insert Activity Conditionally 𝒄 𝒎𝒂𝒙 ≥ 𝒅 𝒎𝒊𝒏

Insert Time Lag 𝒄 𝒎𝒂𝒙 ≥ 𝒕 𝒎𝒊𝒏 𝒄 𝒎𝒊𝒏 ≤ 𝒕 𝒎𝒂𝒙 Dealing with Changes of Time-Aware Processes | Andreas Lanz, Manfred Reichert | 11-09-2014 Insert Time Lag 𝒄 𝒎𝒂𝒙 ≥ 𝒕 𝒎𝒊𝒏 𝒄 𝒎𝒊𝒏 ≤ 𝒕 𝒎𝒂𝒙

Dealing with Changes of Time-Aware Processes | Andreas Lanz, Manfred Reichert | 11-09-2014 Change Operations

Analyzing the Effects Motivation Time-Aware Processes 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

Applying multiple change operations Dealing with Changes of Time-Aware Processes | Andreas Lanz, Manfred Reichert | 11-09-2014 Applying multiple change operations Minimality of the instance time model needs to be restored after each change operation Time complexity 𝑂 𝑛 3 2 𝑚 𝑛 number of time points 𝑚 number of observation time points Significant delays may occur Possible Solution: Approximation How can the “new” instance time model be approximated? Restore minimality of instance time model Update hidden interdependencies Approximate new instance time model Update instance time model Update process model Check applicability of change operation Restore minimality of instance time model Update hidden interdependencies Update instance time model Update process model Check applicability of change operation

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

Example Theorem 1 – Insert Serial Dealing with Changes of Time-Aware Processes | Andreas Lanz, Manfred Reichert | 11-09-2014 Example Theorem 1 – Insert Serial 𝜹= 𝒅 𝒎𝒊𝒏 − 𝒄 𝒎𝒊𝒏 𝑎 𝑚𝑖𝑛 ≤ 𝒂 ′ 𝒎𝒊𝒏 ≤𝑎 𝑚𝑖𝑛 +𝜹 𝑎 𝑚𝑎𝑥 ≥ 𝒂 ′ 𝒎𝒂𝒙 ≥𝑎 𝑚𝑎𝑥 −𝜹 𝑏 𝑚𝑖𝑛 ≤ 𝒃′ 𝒎𝒊𝒏 ≤𝑏 𝑚𝑖𝑛 +𝜹 𝑏 𝑚𝑎𝑥 ≥ 𝒃 ′ 𝒎𝒂𝒙 ≥𝑏 𝑚𝑎𝑥 −𝜹

Multiple Change Operations – Optimized Procedure 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 Update hidden interdependencies Check applicability of change operation Update process model Update instance time model Approximate new instance time model Restore minimality of instance time model Update hidden interdependencies

Applying Multiple Change Operations Dealing with Changes of Time-Aware Processes | Andreas Lanz, Manfred Reichert | 11-09-2014 Applying Multiple Change Operations 4≤14 − 𝛿 4≤10 4≤7 5≤4 5≤10 − 𝛿 5≤6 restore minimality

Applying Multiple Change Operations 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

Conclusion Motivation Time-Aware Processes 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

Summary Time is a fundamental concept for business processes 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

Ongoing and Future Work 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

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 (PlanEx), 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 21st International Conference on Cooperative Information Systems (CoopIS'13), pages 39--56. Springer, 2013. [Lanz et al., 14] Andreas Lanz, Barbara Weber, and Manfred Reichert. Time patterns for process- aware information systems. Requirements Engineering, 19(2):113-141, 2014. [Lanz et al., 14a] 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.