Flat graphical, conceptual modeling techniques are widely accepted as visually effective ways in which to specify and communicate the conceptual data requirements of an information system. Conceptual schema diagrams provide modelers with a picture of the salient structures underlying the modeled

Our goal is to work out an integration process which makes it possible to give a global design schema obtained from several schemas, each of them describing the same reality viewed in different ways, in order to obtain the fullest view. Problems and conflicts arise during the schema integration

The evolution of information systems from their conceptual schemas is an important research area in information systems engineering. In this paper, we aim at contributing to the area by focusing on a particular conceptual modeling construct, the partitions.

Large amounts of data are managed by organizations, available to be viewed and analysed from multiple perspectives, which becomes a fundamental resource to the effectiveness of the organizations. An organization can achieve full benefit from the available information by managing its data resource, through the planning of its exploitation and its maintenance. The concept of data repository fulfils these requirements, due to the fact that it contains the description of all types of data produced, managed, maintained and exchanged in an organization. Data descriptions should be organized in a repository to enable all the users of the information system to understand the meaning of data and the relationships among them.This paper describes two experiences of the use of repositories in Italy for central and local public administrations, showing that the “exact ” methodologies used in the first case with large amount of resources have to be changed into a heuristic step when limited resources are available.

«By synthesis, in its most general sense, I understand the act of putting different representations together, and of grasping what is manifold in them in one knowledge» ([1], p. 94). 1.

The purpose of validating a conceptual schema is to check whether it specifies what the designer intended. Our approach to validation consists in translating the schema into logic in such a way that any reasoning method can be used to perform the validation tests defined by the designer

Conceptual schemas have been recognized as an important tool for the design and evaluation of integrated databases and knowledge-based systems. The paper surveys the back end of a conceptual design methodology called ANNAPURNA. Its theoretical foundation that relies on multi-typed functional

Object oriented models model structural and behavioural aspects of objects in the Universe of Discourse. As the dynamic aspects of objects include parallelism and synchronisation of object life cycles, conceptual schemas must be verified for problematic behaviour like deadlock. In this paper we

In this paper we focus on the transformation of a conceptual schema into an internal schema. For a given conceptual schema, quite a number of internal schemata can be derived. This number can be reduced by imposing restrictions on internal schemata. We present a transformation algorithm that can

Abstract. Like any software artifact, conceptual schemas of information systems can be tested. Testing conceptual schemas has some similarities with testing programs, but there are important differences. We present a list of six kinds of tests that can be applied to conceptual schemas. Some of them