multi-level abstraction techniques – a practical application perspective
DESCRIPTION
Multi-level Abstraction Techniques – A Practical Application Perspective. March 2014. Presentation summary on the work in Neumayr , B., Schrefl , M., & Thalheim , B. (2011). Modeling techniques for multi-level abstraction. The Evolution of Conceptual Modeling , 68–92. Motivation. - PowerPoint PPT PresentationTRANSCRIPT
Multi-level Abstraction Techniques– A Practical Application PerspectiveMarch 2014
Presentation summary on the work inNeumayr, B., Schrefl, M., & Thalheim, B. (2011). Modeling techniques for multi-level abstraction. The Evolution of Conceptual Modeling, 68–92.
Motivation• To reduce accidental complexity of domain models occurring
due to mismatches between a problem and the technology used to represent the problem
• Domain models are increasingly required to support perspectives at different levels of abstraction
• Is there a modelling technique that can reduce complexity while supporting multi-level abstraction?
Introduction
Evaluate multi-level abstraction techniques:– Powertypes (Cardelli)– Deep Instantiation (Atkinson and Kühne)– Materialisation (Pirotte)– M-Objects (Neumayr, B. et al)– HERM (Thalheim, B.)– Component Model (Thalheim, B.)
Evaluation Criteria• Compactness: A domain model is compact if it is modular and
redundancy-free. • Query flexibility: A domain model supports query flexibility if it
provides several pre-defined entry points for querying, such as class names or qualified identifiers to refer to various sets of objects.
• Heterogeneous level-hierarchies: Whether additional abstraction levels can be inserted without affecting the abstraction levels of other domain concepts
• Multiple relationship-abstractions: supports multi-level abstraction of relationships
Multi-Level Abstraction Techniques
Deep Instantiation Refers to meta modelling in which an object at some (meta-)level can describe the common properties for objects at each instantiation-level beneath that level.
Multi-Level Abstraction Techniques
PowertypesA powertype has subclasses of a given class as its instances and allows to describe common properties of these subclasses
Simple pattern
Extended pattern
Multi-Level Abstraction Techniques
Materialization Relates a class of categories (e.g. car models) and a class of more concrete objects (e.g. physical cars)
Multi-Level Abstraction Techniques
M-Objects A multi-level object (m-object) encapsulates the different levels of abstractions that relate to a single domain concept; a multi-level relationship (m-relationship) links two m-objects at multiple levels
Multi-Level Abstraction Techniques
HERM (Higher-order Entity Relationship Model)Extends the classical entity- relationship model by complex attributes, relationship types of higher order, and cluster types.
Overlay schema
Specialisation schema
Multi-Level Abstraction Techniques
Component ModelEnhances the HERM by encapsulation based on component schemata. Components may have various ports and views for exchange. Ports are associated through harnesses.
Multi-Level Abstraction TechniquesResults Compactness Query
FlexibilityHeterogeneous Levels
Relationship Abstraction
Deep Instantiation
Full Full No support Partial
Powertypes (Simple)
Partial Partial No support Partial support using OCL
Powertypes (Extended)
Partial Full Full Partial support using OCL
Materialisation Full Partial No support Partial
M-Objects Full Full Full FullHERM Partial Full with
Overlay Schema
Full with Specialisation Schema
Partial
Component Model
Partial Partial Full Full
Multi-Level Abstraction Techniques
DiscussionWhich criteria are most important to us?
– Heterogeneous Levels– Relationship Abstraction– Query Flexibility– Compactness
Which approach satisfies minimum requirements for modelling abstraction levels of ISO 15926 data model?