1. Allison Barnard-Feeney Dr Phil Spiby
AP233 based CM for SysML
Allison Barnard-Feeney
Dr Phil Spiby

2. Why do this? SysML Model Management identified as major problem
By a few from STEP community years ago
By most in MBSE at IS’08
By most in INCOSE at IW’10
STEP community well versed in complex Change/Configuration Management
Developed PDM Schema in 1990’s
Basis of OMG PDM Enablers and OMG PLM Web Services
Developed PDM Modules in 2000’s
Basis of many PLM tool offerings
AP233 builds upon and extends these capabilities
But harmonized with SysML
Through INCOSE MDSD WG

3. What do we mean by CM? Process for managing change Change request
Change order
Etc.
Meta data recording about the changes
Version identification
Effectivity
Who

4. Formal change management
VDA Recommendation 4965 Part 1: Engineering Change Management
Manage change due to:
Changes in Legislation
Changes in market conditions
Internal inadequacies in development, planning or production
Quality or safety problems
Exploitation of additional optimization potential
Required for large collaborative programs
ECM is the crucial factor in the success of these programs
Cost savings of 43% identified when ECM used
Avoid work on old versions
Prompt response to change

5. Identification and all it means
Identification of an object is fundamental to both AP233 & SysML
BUT what does it mean?
It allows two people to identify the subject in a communication
It is assumed that if two people refer to the same identifier then they are talking about the same thing!
Version identification is Fundamental to model management!
It allows two people to identify the subject at a particular point in time or state in its development
It is assumed that if two people refer to the same identifier and version identifier then the state of that thing is understood
Remember identification and version identification are human actions trying to assert order on complex problems.

6. Effectivity? Effevtivity applies to relationships
It allows tracking of when relationships were effective
In AP233 (and STEP in general) most things are managed as relationships:
Parent/child in an assembly
Property of an object
Classification of an object
Even Identification of an object!
Using effectivity can allow the whole history of development/ change to be recorded
However, this is mostly automatic and not denoted by humans

7. SysML and Change Management
File based
Document management or simple file based PDM
Minimal impact assessment possible
Could be a simple change of layout or complete re-design of model
Diagram Description
Allows version identification & date
Of the Diagram, NOT the model elements on the diagram
More fine grain than file based,
still minimal impact assessment
Vendor tool support
Many vendors now track changes to models within their tools
No support for exchanging/sharing this information
Can lead to tool tie-in

8. AP233 and Change Management
Full PLM support
Versionable objects
Effectivity on relationships
Approval status
Work/process recording

9. AP233/SysML CM support Explicit support for File based management
AP233 Core includes Document Management & PDM
Use file system/Vendor encoded dates?
Mapped support for Diagram based management
AP233 includes collection, so each diagram can be mapped to a versionable collection
Use denotational version identification as given in SysML
However, SysML (and UML), at present, have no standard XMI representation of the diagrams
But most vendors have reasonable (ish!) XMI representations of their diagram structures
Could use vendor specific mappings…

10. AP233/SysML CM support (cont)
SysML artefact mapping
AP233 mapping of SysML artefacts is usually to versionable objects, therefore all SysML artefacts could be version controlled.
However, SysML does not have version information for artefacts
An AP233 based repository system could support “connotational” identification of effectivity information
Allows full rollback capability

11. Recommendation
Mapping from SysML -> AP233 to support ALL CM options
File based
Diagram based
Version information from vendor specific diagram info
Artefact based
Effectivity on relationship allowing roll-backs and dated model development

12. CM based mapping uml:model & xmi:Documentation SysML XMI AP233:
file
uml:model & xmi:Documentation
AP233:
Document Version
SysML
Diagram
AP233:
Collection Version
Vendor specific tags
UML
Package
AP233:
Collection Version
uml:Package
SysML
Block etc
AP233:
Various versionable
objects
SysML::Blocks::Block etc.

13. Connotational effectivity rules
Dependent on what is being imported!
Import relationship into repository:
Same relationship exists
ignore
Same relationship non-existent
Add relationship to repository
Add start-effectivity to relationship
Import source of relationship into repository (i.e. parent)
Import does not include a relationship that was in repository
Ignore if import is partial
Add end-effectivity to existing relationship

14. Mapping from AP233-> SysML (current)
All version and effectivity information lost
However if mapping from a repository the user should be able to select a date and be given the model as it was on that date using effectivity information
All meta data about change process lost

15. SysML Recommendations
Add Id to Block
Currently only Requirements have Id’s
Formalize approach identified in SysML 1.1 Clause
Define standard stereotype ConfigurationItem
Attributes:
author
version
lastChanged
status

16. SysML Recommendations (cont)
Allow encoding of DiagramDescription
Allows tracking of layout changes without semantic change
Attributes:
author
version
lastChanged
status

17. SysML meta model extensions

18. XMI Recommendations
xmi:Documentation should be extended following attributes:
modelVersion
modelDate
modelStatus
Or SysML recommendation that this information is formally encoded into
xmi:Documentation:longDescription

19. Contacts
Allison Barnard-Feeney Address: National Institute of Standards and Technology 100 Bureau Drive, Stop 8260, Gaithersburg, MD USA Telephone: Electronic mail:
Phil Spiby Address: Eurostep Limited 73 Columbia Ave., Sutton in Ashfield, Notts NG17 2GZ UK Telephone: Electronic mail:
This work was performed under contract to NIST