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From Subject Databases to Flow of Responsibility A Retrospective of Three Decades of Modelling. Henk Gazendam University of Twente; University of Groningen Presentation at ICISO 2010, July 19-21, Reading, England. What we are going to do. I. Make OS ontology charting better
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From Subject Databases to Flow of ResponsibilityA Retrospective of Three Decades of Modelling Henk Gazendam University of Twente; University of Groningen Presentation at ICISO 2010, July 19-21, Reading, England
What we are going to do I. Make OS ontology charting better II. Learn from some models I made I11. Conclusion
I. Make OS ontology charting better Affordances, Representations and Objects The Peircean Triad Code Systems Flows of Responsibility
Affordances, Representations and Objects Henk Gazendam. From Subject Databases to Flow of Responsibility
Stamperian Affordance 1 Is a package of behaviour afforded, expected, forbidden, or obligatory in a community Is a social construct Is created whenever a coordination impasse is solved Exists as a habit of action in the mind of people
Stamperian Affordance 2 An affordance refers to Its constitutive event, the event and situation in which it was created Its corresponding social knowledge, the instances of itself known in a community Its determiners, properties of the (external) situation that make its conditions true and activate it
Eco’s Code System 1 A Code System is a set of rules an actor needs to understand in order to translate Signal structures E.g., messages in a language Part of a Syntactic System into Notions about states of the world and Part of a Semantic System Behavioural responses Part of a Behavioural (Pragmatic) System
Eco’s Code System 2 For understanding, the code systems of communicating actors must be compatible For the functioning of social constructs, the conceptual representations of actors in a community must be compatible
Responsibility Responsibility Transfer (RT) is a relationship between affordances next to Ontological Dependency (OD) Normal ontological dependency = OD+RT+ subsequent RT Ontological dependency without responsibility transfer = OD Authorization = OD+RT without subsequent RT
Henk Gazendam. From Subject Databases to Flow of Responsibility
II. Learn from some models I made Learn design principles and modelling improvements from them Models to be explained Government Agency Financial Management Bicycle Shop Logistics Henk Gazendam. From Subject Databases to Flow of Responsibility
Government Agency It is 1975-1985 Transition of tapes to relational databases Transition of mainframes to terminals and PCs I was involved in making an information system architecture for the Government Agency And started with the information chain
P1 The Information Chain Distinguish Data registration at the source Execution of laws and rules Aspect coordination Data gathering for policy making Decision support as separate tasks to be performed by separate actors
Government Agency I learned that Information systems must be based on Tasks of organization units Responsible persons Information systems differ based on their tasks Large-scale data processing Support a specific organization unit Support a person Information systems must reckon with the division of powers within an organization
Government Agency Information System Development can be done an order of magnitude cheaper, and better Then, relational databases, 4th generation languages, modelling tools A factor 29 less costly than previous development (my thesis)
P2 Correspondence Principle The information system you want to design has to correspond to a specific responsible organization unit, user group, or person Information systems that are too large in scope and cross many organizational boundaries tend to be subject of discussion, struggle and failure
P3 Information System Metaphors The Mill is a kind of factory that processes information like water A centralized information system for a large organization. The Cell is an organic information system adapting to the needs of an organization module It should have capabilities for regeneration, change and self-repair The Mind is an intelligent assistant of a person with built-in capabilities for specific task support It can be based on cognitive science, knowledge elicitation and operations research
P4 Division of Powers In society and in organizations there should be a division of powers Trias Politica (legislative, executive, and judiciary) Separation of Church and State Administrative Function Separation within an Organization This leads to a system of checks and balances
P4 Division of Powers Administrative function separation Different Actors responsible for Proposing decisions Financial aspect coordination Cash transfers Bookkeeping Accountant review Each important decision needs at least two sources of information/ opinion Separation of Application Programs Databases of objects, laws and decrees
P5 Mapping to Current Technology Use current analysis patterns Fowler. Analysis Patterns (1997) Hay. Data Model Patterns (1994) Eriksson & Penker. Business Modeling with UML (2000)
P5 Mapping to Current Technology Use current architecture patterns Fowler. Patterns of Enterprise Application Architecture (2003) Hohpe & Woolf. Enterprise Integration Patterns (2004) Use development environments that offer Model-Driven Software Generation Test-Driven Development Implementation of current standards (e.g., FIPA)
Financial Management Around 1985, financial management at the GA needed a new information system Two budget types had to be implemented Encumbrance Commitments, for instance decisions to provide funds to an institution Cash Actual cash flow
P6 The Aspect Phase Model Distinguish (Wisse, 1991) Aspects: decision types to be controlled Phases: steps in decision making, often following a general pattern As orthogonal dimensions of an account
Bicycle Shop A bicycle shop purchases and sells bicycles I used this example for a course in rapid application development Detect requirements, design and program an information system in 3 weeks
P7 The Category Model Distinguish Actors Roles Responsibilities Transactions Phases of transactions Code systems Objects or Events
Bicycle Shop If you have ordered the ontology chart using the category model, it is easy to distinguish object types for design Transaction is added as a supertype for Purchasing =g and Selling/Buying The phases of a transaction are stored in the Transaction using a Phase Code System An Event object type is added to register events in the Transaction life cycle
Bicycle Shop It is also easy to distinguish use cases based on the phases in the ontology chart And the exceptions and extensions
Logistics A logistics company offers an information system for tracking and tracing of goods in the chain consisting of suppliers, shipping companies, factories and storage facilities. The information system has to cooperate with a diversity of customer information systems