Major accidents are characterized by complex causal patterns with many factors influencing the occurrence of such accidents. The causes can be found not just in the execution of the work, but also in the preparations and planning before performing the work. In this paper, we have identified a set of challenges related to planning that may influence major accident risk. The basis is theoretical and partly empirical. The theoretical part is from a study of major accident theories. The empirical part includes studies of investigation reports, interviews and a workshop. The challenges identified can be grouped into four main topics including inadequate plan, inadequate planning, inadequate shared overview and understanding and late risk identification. The challenges have subsequently been addressed through a set of proposed improvements, which are aimed at improving the planning process to better manage major accident risk. (C) 2015 Elsevier Ltd. All rights reserved.