Design Methodology for Ontology-based Multi-Agent Applications (MOMA) Weir Ying Submitted in the total fulfilment of the requirements for the degree of Master of Philosophy (MPhil) March 2009 School of Information Systems, Technology and Management University of New South Wales Australia ORIGINALITY STATEMENT ‘I hereby declare that this submission is my own work and to the best of my knowledge it contains no materials previously published or written by another person, or substantial proportions of material which have been accepted for the award of any other degree or diploma at UNSW or any other educational institution, except where due acknowledgement is made in the thesis. Any contribution made to the research by others, with whom I have worked at UNSW or elsewhere, is explicitly acknowledged in the thesis. I also declare that the intellectual content of this thesis is the product of my own work, except to the extent that assistance from others in the project's design and conception or in style, presentation and linguistic expression is acknowledged.’ Signed ................................................... Date ................................................... Abstract Software agents and multi-agent systems (MAS) have grown into a very active area of research and commercial development activity. There are many current emerging real-world applications spanning multitude of diverse domains. In the context of agents, ontology has been widely recognised for their significant benefits to interoperability, reusability, and both development and operational aspects of agent systems and applications. Ontology-based multi-agent systems (OBMAS) exploit these advantages in providing intelligent and semantically aware applications. In addressing the lack of support for ontology in existing methodologies for multi- agent development, this thesis proposes a design methodology for the building of such intelligent multi-agent applications called MOMA. This alternative approach focuses on the development of ontology as the driving force of the development process. By allowing the domain and characteristics of utilisation and experimentation to be dictated through ontology, researchers and domain experts can specify the agent application without any knowledge of agent design and lower level programming. Through the use of a structured ontology model and the use of integrated tools, this approach contributes towards the building of semantically aware intelligent applications for use by researchers and domain experts. MOMA is evaluated through case studies in two different domains: financial services and e-Health. I Acknowledgements First and foremost, I wish to express my deepest gratitude to A/Prof. Pradeep Ray, my supervisor, for his encouragement, support and valuable guidance to every stage of my research. His devotion is sincerely appreciated. I would also like to thank the students and research fellows from the Asia-Pacific Ubiquitous Healthcare Research Centre (APuHC), Dr. Subhagata Chattopadhyay, Dr. N. Parameswaran, Alfred Wong and Fred Yip. Their criticisms, advice and help with my thesis have proven to be extremely valuable. My appreciation extends to Angalee Sujanani and Jaminda Wimalosiri. Their research provided inspiration and a basis for the case studies in this thesis. Last but not least, I would like to thank my family and friends who have provide d much needed support and understanding throughout my research. II Table of Contents ABSTRACT .................................................................................................................................... I ACKNOWLEDGEMENTS ............................................................................................................... II TABLE OF CONTENTS .................................................................................................................. III TABLE OF CONTENTS .................................................................................................................. III LIST OF FIGURES ......................................................................................................................... VI LIST OF TABLES ......................................................................................................................... VIII LIST OF ABBREVIATIONS ............................................................................................................ IX CHAPTER 1. INTRODUCTION .................................................................................................... 1 1.1 BACKGROUND AND CONTEXT ...................................................................................................... 1 1.2 RESEARCH PROBLEM AND MOTIVATION ........................................................................................ 3 1.3 RESEARCH OBJECTIVES .............................................................................................................. 4 1.4 RESEARCH QUESTIONS .............................................................................................................. 5 1.5 SIGNIFICANCE OF RESEARCH ....................................................................................................... 6 1.6 RESEARCH DESIGN METHODOLOGY .............................................................................................. 7 1.7 ORGANISATION OF THESIS .......................................................................................................... 9 CHAPTER 2. BACKGROUND .................................................................................................... 10 2.1 INTRODUCTION ...................................................................................................................... 10 2.2 AGENT AND MULTI-AGENTS ..................................................................................................... 11 2.2.1 Definition of Agent .................................................................................................. 11 2.2.2 Definition of MAS .................................................................................................... 12 2.2.3 Motivation for agents and MASs ............................................................................. 13 2.2.4 Limitations of Agents and MAS ............................................................................... 14 2.3 ONTOLOGY ........................................................................................................................... 15 2.3.1 What is ontology? ................................................................................................... 15 2.3.2 Benefits and motivation for the use of ontology ..................................................... 16 2.3.3 Motivation for the use of Ontology in MAS ............................................................. 18 2.3.4 Benefits of ontology to MAS development .............................................................. 18 2.3.5 Benefits of Ontology to MAS operations ................................................................. 19 2.4 AGENT-ORIENTED SOFTWARE ENGINEERING ............................................................................... 21 2.4.1 AOSE Methodologies ............................................................................................... 22 2.4.2 Support for Ontology-Based MAS Development ..................................................... 32 2.4.3 Implementation for reviewed methodologies ......................................................... 39 2.5 SUMMARY ............................................................................................................................ 40 CHAPTER 3. DESIGN METHODOLOGY FOR ONTOLOGY-BASED MULTI-AGENT APPLICATIONS (MOMA) 41 3.1 INTRODUCTION ...................................................................................................................... 41 3.1.1 Scope and Limitations.............................................................................................. 42 3.1.2 Overview of MOMA process .................................................................................... 44 3.2 ONTOLOGY DEVELOPMENT ...................................................................................................... 46 3.2.1 Step 1: Concept Identification ................................................................................. 48 3.2.2 Step 2: Ontology Modelling ..................................................................................... 53 III 3.2.3 Step 3: Code Generation .......................................................................................... 71 3.2.4 Tools and techniques ............................................................................................... 72 3.3 AGENT DEVELOPMENT ............................................................................................................ 84 3.4 TESTING ............................................................................................................................... 88 3.5 SUMMARY ............................................................................................................................ 90 CHAPTER 4. CASE STUDY IN THE FINANCIAL SERVICES DOMAIN ............................................ 91 4.1 INTRODUCTION ...................................................................................................................... 92 4.1.1 Financial Multi-agent systems ................................................................................