AN ORGANISATION FOR A NATIONAL EARTH SCIENCE INFRASTRUCTURE

AN ORGANISATION FOR A NATIONAL EARTH SCIENCE INFRASTRUCTURE PROGRAM Information modelling – tools Simon Cox

Overview • A little more UML – Governance concerns, packaging and namespaces • Hollow World interface • Usage guidelines • A few unavoidable details 2

UML structure diagrams

Class diagrams • Show information objects, their properties and relationships Class stereotype Additional parent not shown Specialization Attribute stereotype }Class attributes Association-end role name Association Not shown – class operations }Class constraints

Package diagrams Dependencies & maintenance arrangements

Packaging is important • Unit of governance • UML Package = XML Namespace – If stereotyped «application. Schema» 6

Object diagrams • … can get busy very fast “Accidents in Legoland” Mostly useful in the analysis phase

Summary of UML structure diagrams • Package – ownership (governance arrangements) – dependencies • Class – the data model • Objects – examples in action

Hollow. World

Hollow World template • A template for designing application schemas in UML • Contains key standards components – – ISO 19100 Harmonized Model OGC SWE Model ISO 19136 stereotypes and tagged values INSPIRE themes

Hollow World UI Access to standard/utility components Access to standard stereotypes

ISO Harmonized Model • Key packages used for Application Schema design: – – – – 19103 – primitive types 19107 – geometry 19108 – temporal 19111 – coords 19115 – metadata 19123 – coverages 19136 – GML 19156 – O&M • (go to EA live to explore)

Standard components: OGC Sensor Web • Key packages used for Application Schema design: – – Sensor. ML Observations & Measurements SWE Common SOS, SPS. . . • (go to EA live to explore)

Elements from external standards • Standard components are loaded from remote SVNs • They are locked against modification by unauthorized users (i. e. mere application-schema designers!) – i. e. the tool enforces the governance arrangements • Package your domain model separately

High level usage guidelines

Use of UML • Informative - sketch or illustrate ideas – Ambler (Agile methodologies …) uses it mostly this way vs. • Formal & complete – In order to feed a CASE tool • For automatic implementation, the model must be complete – Everything required for implementation must be in either • The model • The rule for converting from model to implementation – UML == ‘graphical programming language’ • Every comma counts, just like real programming

Be aware of the workflow • Raw observations – E. g. temperature field, flow-rate history, density distribution, colour distribution (image) – i. e. evidence • Interpolated/modelled properties – Geophysics, Met. Ocean – Results of simulations and process models, conditioned by observations – i. e. predictions, simulations, inversions • ‘Real-world’ features – E. g. weather system, ore-body, forest, reef – i. e. result of interpretation • Often useful to segregate these viewpoints into different packages

Be consistent about the abstraction level • Conceptual - Domain semantics – Terminology as used by practitioners in the discipline • not an abstraction from data management – ‘Ore-body’, not ‘Table’ or ‘Polygon’ or ‘URI’ • Don’t show identifier, key/keyref in the class model – these are implicit in the relationships • Implementation – Shows implementation artefacts like ‘string’, ‘id’, ‘index’

Document as you go 19

More information • For more detail: – https: //www. seegrid. csiro. au/twiki/bin/view/App. Schemas/Uml. Outline – https: //www. seegrid. csiro. au/twiki/bin/view/App. Schemas/Uml. Gml. Stereotypes. And. Tagged. Val ues – https: //www. seegrid. csiro. au/twiki/bin/view/App. Schemas/Uml. Gml. Test. Models

UML extensibility points

UML extensions • Stereotypes – Extend the meta-model: – To create an additional class-of- [classes, associations, attributes]

UML Stereotypes «Feature. Type» standard properties & behaviour

Class stereotypes • «Feature. Type» – Domain class, instances have identity • «Type» or none – Has identity, but not a feature; e. g. geometry, topology, temporal object, definition • «Data. Type» – Just a data structure, no external identity, always inline • «Union» – Ad-hoc choice • «Enumeration» – Closed enumeration • «Codelist» – Extensible enumeration

Package stereotypes • «Application Schema» – independently governed package, separate XML namespace • «Leaf» – Convenience package, no subpackages, separate XSD document

UML extensions • Stereotypes • Tagged values – Embed information for specific implementation platforms – Doesn’t relate to the conceptual level

UML Tagged values

Tagged values for GML encoding • Package – xsd. Document – xmlns – target. Namespace • Class – – no. Property. Type by. Value. Property. Type as. Dictionary ( «code. List» only) owned. By (proposed) • Attribute and association end – sequence. Number – inline. Or. By. Reference – estimated. Property (proposed) https: //www. seegrid. csiro. au/twiki/bin/view/App. Schemas/Uml. Gml. Stereotypes. And. Tagged. Values

Acknowledgements • SISS Project Sponsors: • Au. Scope, ANDS and the ARCS Organisations are supported by the Australian Government through the National Collaborative Research Infrastructure Strategy Program and/or the Education Investment Fund (EIF) Super Science Initiative • Workshop assistance provided by:

Au. Scope 2007 -2011 AN ORGANISATION FOR A NATIONAL EARTH SCIENCE INFRASTRUCTURE PROGRAM