ABSTRACT Decommissioning of nuclear facilities is a rapidly growing field in which construction techniques are applied within a dangerous environment. Radiation and contamination complicate the design of the decommissioning process. The main objectives of decommissioning are to maintain a safe environment for workers and to avoid loosing material. Secondly, the decommissioning process shall minimize the amount of contaminated material that must be stored safely for a long time. Decommissioning processes, as well as construction processes, often consist of several inter-related tasks. During the decommissioning process planning, several feasible procedures for each task must be evaluated within the context of the overall system and regarding delivery of customer value. This paper documents a case-study during which a two staged set-based planning approach was applied to rigorously explore the planning space of a dismantling process at a nuclear power plant in Germany. The result of the planning process was then verified through a survey of experienced practitioners