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Thursday, 23 May 2013 02:36

Pattern TP1: Time Lags between two Activities

This pattern allows defining time lags between two activities; i.e., to express a minimum or maximum temporal distance between them.

Also known as

Upper and Lower Bound Constraints, Inter-Task Constraints, Temporal Relations

Problem

There is a time lag between two activities to be obeyed. Such Time Lags may not only be defined between directly succeeding activities, but also between arbitrary ones (presuming that the activities may belong to the same process instance).

Design Choices

C Time lags only constrain the execution of activities
a Single activity (including multi-instance activities)
D There are three kinds of restrictions
a Minimum value
b Maximum value
c Time interval [min … max]
E Time lags define the distance between the
a start of two activities (i.e., Start-Start relation)
b start of the first and the completion of the second activity (i.e., Start-End)
c completion of the first and the start of the second activity (i.e., End-Start)
d completion of two activities (i.e., End-End)

TimeLagsActivitiesSolution

A time constraint is introduced between the start / end event of the two activities.

 Timers can be used to realize this pattern at run-time. For example, to implement an end-start relation between activities A and B, the timer starts after completing A. If the time lag between A and B represents a minimal one, B must not be started before the timer has expired; i.e., the execution of activity B is delayed until the time lag is satisfied. If the time lag expresses a maximum distance, B may be started immediately, but has to be started latest when the timer expires. In case the timer expires an exception handling may be triggered. For time intervals both cases apply.

Context

The mechanism evaluating the constraint (i.e., starting the timer) needs to be able to access the value of the time lag when starting the timer. Examples

  • The maximum time lag between discharging a patient from a hospital and sending out the discharge letter to the general practitioner treating the patient is 2 weeks (Design Choices D[b] E[d] )
  • Patients must not eat at least 12 hours before a surgery takes place. The latest point in time at which the patient can have a meal is therefore determined by the date of the surgery (Design Choices D[a] E[c])
  • The time lag between registering a Master thesis and submitting it must not exceed 6 months (Design Choices D[b] E[a] )

Examples

  • The maximum time lag between discharging a patient from a hospital and sending out the discharge letter to the general practitioner treating the patient is 2 weeks (Design Choices D[b] E[d] )
  • Patients must not eat at least 12 hours before a surgery takes place. The latest point in time at which the patient can have a meal is therefore determined by the date of the surgery (Design Choices D[a] E[c])
  • The time lag between registering a Master thesis and submitting it must not exceed 6 months (Design Choices D[b] E[a] )

Related Patterns

Animation

Product Evaluation

We differentiate between supported, partially supported, not supported and not specified.
If an evaluation object provides support for the particular pattern the supported design choices are listed. If the pattern is only partially supported (e.g., by a work-around) this is indicated by the additional label "*" and if support is not specified this is indicated by the label "?". Missing support is labeled with "-".

Product/LanguageVersionScoreMotivation
Microsoft Outlook 2010 No constraints on time lags between activities supported
Sunbird 1.0 No constraints on time lags between activities supported
Google Calendar 12.2011 No constraints on time lags between activities supported
Microsoft Project 2010 D[a,b], E[a,b,c,d] supported
BPMN 2.0 D[a,b*,c*], E[c*] partially supported
IBM Websphere Integration Developer 6.1 D[b], E[c,d*] partially supported; directly succeeding activities only
WebSphere Lombardi Edition 7.1 D[a,b*], E[a*,b*,c,d*] work-arounds are needed, not all combinations are supported
AristaFlow 1.0.1 D[b], E[d*] partially supported (with limits)
Intalio 6.0.3 D[a,b*,c*], E[c]
TIBCO Business Studio 3.4.2 D[a,b*,c*], E[c] supported
Bettini et al. D[a,b,c], E[a,b,c,d] fully supported
Combi et al. D[a,b,c], E[a,b,c,d] supported
Eder et al. D[a,b,c], E[d] partially supported
Marjanovic et al. D[a,b,c], F[a,b,c,d] full support
Zhuge et al. D[a,b,c], E[c*] partially supported
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Involved Partners

andreaslanz 50

 

Andreas Lanz
University of Ulm, Institute of Databases and Information Systems

 

 

manfredreichert 50

Manfred Reichert
University of Ulm, Institute of Databases and Information Systems

 

 

barbaraweber 50

Barbara Weber
University of Innsbruck, Department of Computer Science

 

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Important Publications

Lanz, A. and Weber, B. and Reichert, M. (2012) Time patterns for process-aware information systems.Requirements Engineering.

 

Lanz, A. and Weber, B. and Reichert, M. (2010) Workflow Time Patterns for Process-aware Information Systems. In: BPMDS'10.