View TRAK:SVp-11 Solution Event Causes Viewpoint

Title

TRAK_logo_60.jpg

SVp-11 - Solution Event Causes Viewpoint

Version

1

Date

1st January 2016

Overview

The SVp-11 - Solution Event Causes is part of the TRAK Solution Perspective and one of the 24 TRAK Architecture Viewpoints.

The SVp-11 architecture viewpoint is the specification for the TRAK::SV-11 Solution Event Causes architecture view.

Stakeholders Addressed

  • Owner of Solution
  • Acquirer of Solution
  • Developer of Solution
  • Builder of Solution
  • Operator of Solution
  • Trainer of Solution
  • Maintainer of Solution
  • User of Solution

Covered by TRAK IPR and licenses

Concerns Addressed

The SVp-11 addresses the following concerns:

  • how robust is the system to unwanted events?
  • how dependable is the system?
  • what causes (feared) events?

Covered by TRAK IPR and licenses

Anti-Concerns

  • intended or specified function (behaviour) - this is described using the SVp-04 Solution Function viewpoint

 

Covered by TRAK IPR and licenses

Description

Describes causal or contributory relationships between events that are associated with the system of interest either owing to an error within the system or direct action from something external to the system

Typically used to represent:

  • fault trees for safety to identify a causal chain of events that lead to a set of top ‘feared events’ which need to be managed
  • reliability analyses that provide the basis for predicting how reliable (dependable) a system is in delivering its intended behaviour or level of performance.
  • the architecture within a solution that makes it robust in the presence of behaviours or inputs that affect its ability to deliver its intended behaviour or performance (diversity, redundancy, fault-tolerance etc.)

The events are typically associated with a failure to follow specified behaviour or a failure to anticipate or specify all the required behaviour as opposed to the SVp-04 Solution Function viewpoint which describes specified (normal) behaviour.  Events may be caused by the system of interest or by external systems or ‘actors’. This viewpoint therefore provides a means to anticipate what happens when things go wrong.

Covered by TRAK IPR and licenses

Mandatory Metamodel Tuples

  • Event caused by Event
  • Event caused by Resource
  • Event caused by Function
  • Event impacts on Resource
  • Event impacts on Function

Covered by TRAK IPR and licenses

Optional Metamodel Tuples

  • Resource performs Function
  • Event poses Risk

Universal

If any of these optional metamodel elements are added then the appropriate TRAK Master Architecture View must be provided.

Covered by TRAK IPR and licenses

Well-Formedness

A SV-11 shall contain:

  • at least one (the subject) Event
  • the subject Event is linked to at least one Resource using either ‘Event caused by Resource’ or ‘Event impacts on Resource’
  • the subject Event is linked to one or more events that cause the subject Event. If a combination of events are needed to cause the event this shall be stated using a boolean logical operator (e.g. AND, OR, NOT, XOR or any combination).
  • IF a Function is linked to an Event using EITHER(‘Event impacts on Function’  OR ‘Event is caused by Function’) THEN the associated Resource shall be shown using ‘Resource performs Function’.

Covered by TRAK IPR and licenses

 

Presentation

  • graphical, showing a tree depicting the causal relationships e.g. a fault tree, visualisation of tuples.
  • textual e.g. set of tuples as assertions.
    • Event. Hazardous Radiation Dose Exposure caused by System. Linear Accelerator
    • Event. Hazardous Radiation Dose Exposure caused by ((Event. Dose set too high AND Event. Alarm not activated)) OR (Event. Dose set correctly AND Event. Radiaton))

Since a boolean logic operator is dimensionless the combination Event AND/OR/etc. Event is itself an Event.

Covered by TRAK IPR and licenses

Examples

Views Needed to Construct

See Minimum Allowed View Sets

The SV-11 is the master architecture view for Event.

Covered by TRAK IPR and licenses

Consistency Rules

  • any relationship with Function must be consistent with the Resource performing the Function:-
    • IF Event caused by Function AND Resource performs (same) Function THEN Event caused by (same) Resource.
    • IF Event impacts on Function AND Resource performs (same) Function THEN Event impacts on (same) Resource.

Covered by TRAK IPR and licenses

Configuration History

The TRAK Viewpoints project on Sourceforge (trakviewpoints.sourceforge.net) maintains a version-controlled repository. The change record is at trakviewpoints.svn.sourceforge.net/viewvc/trakviewpoints/trunk/?view=log

Comments

References

Other Frameworks

There are no equivalent views in MODAF, DODAF or NAF

References


Category:Framework -> Viewpoint
Category:Framework -> Specification
Category:Solution

Categories:

  • Solution
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