1 Modelling Concepts for the Representation of Evolution Constraints Christophe Claramunt 1 and Christine Parent 2 1 The Nottingham Trent University Department of Computing Nottingham, NG1 4BU, UK clac@doc.ntu.ac.uk 2 University of Lausanne HEC Inforge, Lausanne, CH 1015, Switzerland Christine.Parent@hec.unil.ch Abstract. During the past years several design methods have been successfully applied for the design of databases in many application areas. However, the database modelling of the behaviour of dynamic systems is still a challenging open issue, particularly for applications with an important temporal component. The recent integration of the temporal dimension within database modelling methods provides a first step towards the representation of the dynamics of evolving systems. This paper proposes a set of modelling concepts oriented towards the description and representation of constraints that restrict the evolution of entities. We make a distinction amongst evolutions that are characterised by either a migration of an entity towards another entity type, generation or deletion of an entity, or change of value of an entity attribute. These modelling concepts are illustrated in the context of an urban database. 1 Introduction Conceptual database models favour a high-level communication support between database designers and the application level. Database schemas are often represented by graphic diagrams, e.g., an Entity-Relationship schema that provides a user-oriented visual representation of the application semantics. The development of conceptual database models has been recently re-visited due to recent progress in the integration of the temporal and spatial dimensions within databases [21]. Among the proposed models that include the temporal dimension, most come with temporal constraints that are automatically associated to the modelling concepts: the constraints are inherent to the data model. For instance, the life span of a temporal relationship must be included in the life spans of the linked entities. However, some applications may not obey such a predefined constraint that would contradict the application semantics [18]. Proposals that do not include inherent constraints let database designers define whatever