This paper discusses IS strategising and how the combination of the planning and the incremental approaches can enable successful IS strategising. IS strategising is conceptualised as a dual organisational process in which the network and the hierarchy positively coexist through group-learning processes. The findings from two case studies illustrate the theoretical framework. An analysis of 28 interviews reveal the complexity of IS strategising and show that IS strategising is best understood as a dual dynamic-interactive processing which the choice of strategic approach is not a dichotomy but more of a both/and decision. The overall conclusion is that IS strategy, because of increased uncertainty and environmental complexity, must encourage interaction between key stakeholders who implement and use the IS technology. The dual organisation and the experience-based group-learning processes help organise the process of IS strategising so that improvisational and dynamic competencies can emerge.