Contribution to the definition of contingent approaches in information system development : proposition of a key-problem identification oriented approach ; Contribution à la définition de processus contingents en développement de systèmes d'information : proposition d'une démarche orientée identification des problèmes-clés

Information systems (IS) take nowadays a central place at alllevels of organizations. However in spite of numerous methods, over 60 % of IS development projects fait. Facing to this surprising situation, we focus on the approaches enabling project success. The contingent and modular approaches which propose to adapt the methods and project tasks to the context seem to be interesting. Our research deals with improvement of such approaches. We first propose a framework in order to come back up to the underlying principles of existing contingent approaches. This analysis emphasizes on method adapation through project task adaptation and on application difficulties. Indeed, adaptation qliality is linked to the quantification of indicators which can only be quantified precisely at the end of the project, when it is unnecessary. In order to better exploit existing approches it is necessary to use other concepts which are not linked to organizational and technical elements of the project. The concept of problem is such a concept. Sb, we rely on the principles of OTSM-TRIZ, general method of problem formulation and solving. This method formulates the problems in the form of contradictions. Here, we propose to formulate generic contradictions of evolution. These contradictions are key-problems to solve during IS development projects in general. Then we propose an approach to exploit these key-problems during a particular project. In other words a project is here characterized through its key problems. This approcah isiullustrated through a study case dealing with the follow-up ofproducts in a workshop. ; Les systèmes d'information (SI) ont de nos jours une place centrale à tous les niveaux des organisations. Malgré une "jungle méthodologique ", les projets de développement n'apportent pas toujours satisfaction. Or, les processus contingents et modulaires c'est-à-dire permettant l'adaptation des méthodes et des tâches projet au contexte semblent intéressants pour favoriser le succès des projets. Notre travail se place ...