Perbandingan Pengaruh Teknik Pemodelan Entity-relationship Model dan Resources-events-agents Model Atas Perancangan Database Perusahaan

Databases are an important part of most computer-based information systems. As such, the design of a database has also gained importance because a bad design will compromise data integrity as well as make it inefficient in its use of resources. This paper compares the effect of two data modeling approaches on the design of a database, specifically the Entity-Relationship Model (ER Model) and the Resources-Events -Agents Model (REA Model). First, the sales/collection cycle of a fictional case study is described. Then, an ER Model and a REA Model are independently created based on this case study. Finally, one database design is created based on the ER Model, and another database design is created based on the REA Model. The outcome of this experiment shows that both approaches produced similar database designs, but the design processes were different in their complexity, structurally, and completeness. A significant difference is that the ER Model closely followed those aspects that were already laid out by the case study, while the REA Model started out by building a most complete data model, over and above the one described in the case study

Perbandingan Pengaruh Teknik Pemodelan Entity-relationship Model dan Resources-events-agents Model Atas Perancangan Database Perusahaan

Databases are an important part of most computer-based information systems. As such, the design of a database has also gained importance because a bad design will compromise data integrity as well as make it inefficient in its use of resources. This paper compares the effect of two data modeling approaches on the design of a database, specifically the Entity-Relationship Model (ER Model) and the Resources-Events -Agents Model (REA Model). First, the sales/collection cycle of a fictional case study is described. Then, an ER Model and a REA Model are independently created based on this case study. Finally, one database design is created based on the ER Model, and another database design is created based on the REA Model. The outcome of this experiment shows that both approaches produced similar database designs, but the design processes were different in their complexity, structurally, and completeness. A significant difference is that the ER Model closely followed those aspects that were already laid out by the case study, while the REA Model started out by building a most complete data model, over and above the one described in the case study

UML Class Diagram or Entity Relationship Diagram : An Object Relational Impedance Mismatch

It is now nearly 30 years since Peter Chen’s watershed paper “The Entity-Relationship Model –towards a Unified View of Data”. [1] The entity relationship model and variations and extensions to ithave been taught in colleges and universities for many years. In his original paper Peter Chen looked at converting his new ER model to the then existing data structure diagrams for the Network model. In recent years there has been a tendency to use a Unified Modelling Language (UML) class diagram forconceptual modeling for relational databases, and several popular course text books use UMLnotation to some degree [2] [3]. However Object and Relational technology are based on different paradigms. In the paper we argue that the UML class diagram is more of a logical model (implementation specific). ER Diagrams on theother hand, are at a conceptual level of database design dealing with the main items and their relationships and not with implementation specific detail. UML focuses on OOAD (Object Oriented Analysis and Design) and is navigational and program dependent whereas the relational model is set based and exhibits data independence. The ER model provides a well-established set of mapping rules for mapping to a relational model. In this paper we look specifically at the areas which can cause problems for the novice databasedesigner due to this conceptual mismatch of two different paradigms. Firstly, transferring the mapping of a weak entity from an Entity Relationship model to UML and secondly the representation of structural constraints between objects. We look at the mixture of notations which students mistakenly use when modeling. This is often the result of different notations being used on different courses throughout their degree. Several of the popular text books at the moment use either a variation of ER,UML, or both for teaching database modeling. At the moment if a student picks up a text book they could be faced with either; one of the many ER variations, UML, UML and a variation of ER both covered separately, or UML and ER merged together. We regard this problem as a conceptual impedance mismatch. This problem is documented in [21] who have produced a catalogue of impedance mismatch problems between object-relational and relational paradigms. We regard the problems of using UML class diagrams for relational database design as a conceptual impedance mismatch as the Entity Relationship model does not have the structures in the model to deal with Object Oriented concepts Keywords: EERD, UML Class Diagram, Relational Database Design, Structural Constraints, relational and object database impedance mismatch. The ER model was originally put forward by Chen [1] and subsequently extensions have been added to add further semantics to the original model; mainly the concepts of specialisation, generalisation and aggregation. In this paper we refer to an Entity-Relationship model (ER) as the basic model and an extended or enhanced entity-relationship model (EER) as a model which includes the extra concepts. The ER and EER models are also often used to aid communication between the designer and the user at the requirements analysis stage. In this paper when we use the term “conceptual model” we mean a model that is not implementation specific.ISBN: 978-84-616-3847-5 3594Peer reviewe

Some Ontological Issues of the REA Framework in Relation to Enterprise Business Process

The aim of the paper is to describe using REA framework to model enterprise planning not only at the operational level but also at the policy level. Using policy level enlarges the possibility of the models on the base of the REA framework because the policy level in this way represents metalevel of the model. The policy level of the REA framework itself is comprised both of the entities related by typification, grouping and policy relationships and of the Commitment entity with the fulfillment relationship. This entity may be viewed as either a sublayer or a middle layer of the REA framework. The Commitment entity belongs to the fundamental entities of the policy level but has some specifications that are expressed by the fulfillment relationship. This many-to-many relationship forms the link to the operational level. In the paper we discuss the problem and suggest some solution that moves the Commitment entity closer to the typification and grouping semantic abstractions.REA ontology; enterprise business process; semantic abstractions

Enterprise planning model using REA ontology

The aim of the paper is to describe using REA framework to model enterprise planning not only at the operational level but also at the policy level. Using policy level enlarges the possibility of the models on the base of the REA framework because the policy level in this way represents metalevel of the model. The policy level of the REA framework itself is comprised of both the typification and grouping semantic abstractions and the Commitment entity. This entity may be viewed as either a sublayer or a middle layer of the REA framework. The Commitment entity belongs to the fundamental entities of the policy level but has some specifications that are expressed by the fulfillment relationship. This many-to-many relationship forms the link to the operational level. The paper thinks over the problem and suggests some solution that gets the Commitment entity closer to the typification semantic abstraction.REA framework; policy level; production planning model; typification; grouping; cardinality

SOME ONTOLOGICAL ISSUES OF THE REA FRAMEWORK IN RELATION TO ENTERPRISE BUSINESS PROCESS

The aim of the paper is to describe using REA framework to model enterprise planning not only at the operational level but also at the policy level. Using policy level enlarges the possibility of the models on the base of the REA framework because the policy level in this way represents metalevel of the model. The policy level of the REA framework itself is comprised both of the entities related by typification, grouping and policy relationships and of the Commitment entity with the fulfilment relationship. This entity may be viewed as either a sub layer or a middle layer of the REA framework. The Commitment entity belongs to the fundamental entities of the policy level but has some specifications that are expressed by the fulfilment relationship. This many-to-many relationship forms the link to the operational level. In the paper we discuss the problem and suggest some solution that moves the Commitment entity closer to the typification and grouping semantic abstractions.REA ontology, enterprise business process, semantic abstractions