Today's economic systems are characterised by flexible specialisation driven by a growth of service-based firms, a servicification of manufacturing firms and projectification. There is therefore a growing number of matrix organisations being co-dependent on line organisations and projects. The study aims to advance theorising on such organisations by empirically studying the assumption that tensions act as drivers for managerial action in project organisations and that they constitute a foundation upon which theories may be built. The study shows that tensions are concerns in project organisations and that sources of tensions are primarily created by the coexistence of fundamentally different organising principles, the way employees identify themselves with either the line function or with projects and by competition for limited organisational resources. The study differentiates project-oriented organisations and project-based organisations from one another. The main contribution is to empirically study and validate Lundin and Soderholm's (1995) [Lundin, R. A., Et Soderholm, A. (1995). A theory of the temporary organisation. Scandinavian Journal of Management, 11, 437-455] theory on temporary organisation. (C) 2008 Elsevier Ltd. All rights reserved.
