1. Copyright: SIPC Reference Data Architecture and Standards An Introduction to ISO15926 Matthew West

2. Reference Data Architecture and Standards 2 Programme Introduction to 4 Dimensionalism ISO 15926-2 – Lifecycle Integration Schema – Introduction to the data model

3. Reference Data Architecture and Standards 3 3D and 4D approaches to ontology In principle, there are infinitely many ways in which we can model the world, so it is perhaps surprising that there are two main approaches, with on the whole minor variations, that dominate the literature.We will call these the 3D paradigm and the 4D paradigm, though they are also known as endurantism, and perdurantism.

4. Reference Data Architecture and Standards 4 4D Ontology A 4D ontology treats all individuals – things that exist in space-time - as spatio-temporal extents, i.e. as 4D objects. The principles of the 4D paradigm are: 1.Individuals exist in a manifold of 4 dimensions, three space and one time. So things in the past and future exist as well as things in the present. 2.The four dimensional extent is viewed from outside time rather than in the present. 3.Individuals (including physical objects) extend in time as well as space and have both temporal parts and spatial parts. 4.When two individuals have the same spatio-temporal extent they are the same thing. (However not all version of 4D insist on this principle). Thus a 4D object is not (usually) wholly present at a point in time, but its whole is extended in space as well as time. The object at a point in time is a temporal part of the whole. Change is naturally expressed through a 4 dimensional classical mereology, which Simons: “ Parts: A Study in Ontology ” in his seminal work, describes in one page. A good description of, and argument for, the 4D paradigm can be found in Sider: “ 4 Dimensionalism ”.

5. Reference Data Architecture and Standards 5 3D Ontology A 3D ontology treats physical objects (roughly things you can kick) as 3D objects (sometimes called continuants) that pass through time. The principles of the 3D paradigm are: 1.Physical objects are 3-dimensional objects that pass through time and are wholly present at each point in time. 2.Physical objects are viewed from the present. The default is that statements are true now. 3.Physical objects do not have temporal parts. 4.Different physical objects may coincide. 5.The object-at-a-point-in-time is the object of primary interest. To talk about an object at different times it is necessary to time index statements in some way, e.g. X at t. A 3D ontology also has 4D objects in it. These cover activities, such as: –a football match - which clearly has temporal parts such as the first half and the second half, –a living process - a persons life, rather than the physical person passing through time.

6. Reference Data Architecture and Standards 6 Which paradigm? The 3D approach corresponds well with the way that language works. Language has a focus around here, now, you and me as a context, and on the current state of affairs. This leads to efficient communication under the most common circumstances. On the other hand dealing with change is relatively problematic. Simons requires several chapters to explain how objects change over time in a 3D ontology. What is clear is that the 3D and 4D paradigms cannot be merged into a single canonical approach, since they are contradictory, with one requiring physical objects to have temporal parts, and the other forbidding them. On the other hand, it appears that what can usefully be said using one paradigm can generally be said using the other. We chose the 4D paradigm because we found it to be rigorous, and gave a good account of some difficult cases, like replaceable parts.

7. Reference Data Architecture and Standards 7 ISO15926-2: Integration Model Background – Originally the EPISTLE Core Model – Started around 1993 – Now at Version 4.5.1 – As ISO 15926-2 became an International Standard in 2003. – http://www.tc184-sc4.org/wg3ndocs/wg3n1328/lifecycle_integration_schema.html http://www.tc184-sc4.org/wg3ndocs/wg3n1328/lifecycle_integration_schema.html

8. Reference Data Architecture and Standards 8 Basic Elements Thing – anything, real or abstract – Note: the supreme supertype Possible Individual (Spatio-temporal extent) – some part(s) of space-time Class – collection of things, possibly infinite, where the order is not significant Relationship – Something one thing has to do with another.

9. Reference Data Architecture and Standards 9 TIME 3D SPACE Space time map A particular spatio temporal extent

10. Reference Data Architecture and Standards 10 Thing

11. Reference Data Architecture and Standards 11 Possible Worlds PastFuture Actual Possible Desired

12. Reference Data Architecture and Standards 12 TIME 3D SPACE  T > 0  S > 0 Possible Individual

13. Reference Data Architecture and Standards 13 Plastic blank Cup Crushed plastic TIME Whole Individual

14. Reference Data Architecture and Standards 14 TIME 3D SPACE  T = 0  T > 0 period of time point in time

15. Reference Data Architecture and Standards 15 TIME 3D SPACE State Time period Individual Possible Individual/State – Temporal whole-part

16. Reference Data Architecture and Standards 16 3D space Time A B C D event 1event 2 Materialised Physical Object

17. Reference Data Architecture and Standards 17 installed TIME 3D SPACE removed installed pump 1 pump 2 Tag 101 Functional Physical Object/Replaceable Part

18. Reference Data Architecture and Standards 18 Objects that Overlap Space Chairman of Shell John Jennings Mark Moody-Stuart

19. Reference Data Architecture and Standards 19 3D space Time valve open valve close tank A tank B connected disconnected hose start filling end filling Stream

20. Reference Data Architecture and Standards 20 Individual

21. Reference Data Architecture and Standards 21 Activity 3D space Time Activity Performer Input Output Input Output Performer

22. Reference Data Architecture and Standards 22 TIME 3D SPACE  T = 0 event Point in time Event and Point in Time

23. Reference Data Architecture and Standards 23 TIME 3D SPACE Sub state event point in time Temporal Boundary

24. Reference Data Architecture and Standards 24 Activity and Temporal Boundary

25. Reference Data Architecture and Standards 25 Some approaches to Set Theory A BC 123456 Instances may only be a member of only one set Only one level

26. Reference Data Architecture and Standards 26 Some approaches to Set Theory A BC 123456 MOPN X YZ Instances may only be a member of only one set Sets hierarchical (model/meta-model etc)

27. Reference Data Architecture and Standards 27 Some approaches to Set Theory A BC 123456 MOPN X YZ Instances may only be a member of one or more sets Sets hierarchical (model/meta-model etc)

28. Reference Data Architecture and Standards 28 Some approaches to Set Theory A BC 123456 MOPN X YZ Instances may only be a member of one or more sets Sets not hierarchical (model/meta-model etc)

29. Reference Data Architecture and Standards 29 Some approaches to Set Theory A BC 123456 MOPN X YZ Instances may only be a member of one or more sets Sets not hierarchical (model/meta-model etc). Loops allowed

30. Reference Data Architecture and Standards 30 Class

31. Reference Data Architecture and Standards 31 Class of Individual

32. Reference Data Architecture and Standards 32 “fundamental” particle assembly simple artefact molecular atomic sub-atomic organisation organism time Organisational Levels

33. Reference Data Architecture and Standards 33 Cup Plastic Hydrocarbon molecules atoms arrangement of

34. Reference Data Architecture and Standards 34 Organisational Levels

35. Reference Data Architecture and Standards 35 Information

36. Reference Data Architecture and Standards 36 Information

37. Reference Data Architecture and Standards 37 Information

38. Reference Data Architecture and Standards 38 Summary A 4D ontology sees physical objects as extended in time as well as space ISO 15926 is a data model that is also a 4D ontology It uses a possible worlds approach rather than modal logic Sets are defined by extension

39. Reference Data Architecture and Standards 39 Questions?