Unit 5: Object-Role Modeling (ORM)

Transcription

1 Modeling in Business in Information Systems Unternehmensmodellierung und -architekturen Unit 5: Object-Role Modeling (ORM) Professur für Allgemeine BWL, insbesondere E-Business This unit is based on: Terry Halpin: Object Role Modeling: An Overview, White Paper,

2 Course Overview 1 Introduction 2 Modeling for Beginners: Conceptual Structures and Processes 3 Modeling Conceptual Structures 4 Process Modeling: Behavioral Aspects of Information Systems 5 ARIS Architecture of Integrated Information Systems 6 Challenges in Information Systems Modeling 7 Reference Models and Process Libraries 8 Collaboration in Modeling 9 Ontologies and Ontology Engineering 10 Ontological Analysis of Models 11 Tools 12 Exercises 13 Additional Topics DPM - Unit 3 2

3 Unit 6: Object-Role Modeling Limitations of Entity-Relationship Modeling Foundations of Fact-based Modeling Conceptual Schema Design Procedure (CSDP) Step 1: Transforming examples into elementary facts Step 2: Draw fact types and apply population check Step 3: Check for entity types that should be combined; note arithmetic derivations Step 4: Add uniqueness constraints, and check arity of fact types Step 5: Add mandatory role constraints, and check for logical derivations Step 6: Add value, set comparison and subtyping constraints Step 7: Add other constraints and perform final checks Examples DPM - Unit 3 3

4 Limitations of Entity-Relationship Modeling Although ER models can be of use once the design process is finished, they are less suitable for formulating, transforming or evolving a design. ER diagrams are further removed from natural language, cannot be populated with fact instances, require complex design choices about attributes, lack the expressibility and simplicity of a role-based notation for constraints, hide information about the semantic domains which glue the model together, and lack adequate support for formal transformations. DPM - Unit 3 4

5 Foundations of Fact-based Modeling Specify the information structure of the application Types of facts that are of interest Constraints on these Derivation rules for deriving some facts from others DPM - Unit 3 5

6 Conceptual Schema Design Procedure (CSDP) DPM - Unit 3 6

7 Step 1: Transforming examples into elementary facts DPM - Unit 3 7

8 Step 1: Transforming examples into elementary facts DPM - Unit 3 8

9 Step 2: Draw fact types and apply population check DPM - Unit 3 9

10 Step 2: Draw fact types and apply population check DPM - Unit 3 10

11 Step 3: Check for entity types that should be combined; note arithmetic derivations DPM - Unit 3 11

12 DPM - Unit 3 12

13 Thank you. Professur für Allgemeine BWL, insbesondere E-Business