Based on empirical material from the area of software engineering, this articlediscusses the issue of plans and planning as an integral part of and prerequisite for software development work. It relates observed practices to literature produced by the Computer Supported Cooperative Work community. Empirical studies of software development practice seldom address re-planning. By analyzing the empirical material from one project we are able to show how certain kinds of co-ordination problems arise and how they may be dealt with. The empirical research does not focus primarily on the character of plans; instead, it raises the question ‘what means are necessary and should be provided in order to cope with situations when plans do not work out? In relation to plans, especial emphasis is on ‘‘due process’’, i.e. how the project plan and the company wide project model are maintained to enable the identification and articulation of deviations from it. On the basis of our empirical analysis we propose to support the articulation and coordination work necessary in situations where plans do not adequately work out.