To proactively decide on the volume of capacity available in a period of time is referred to as capacity dimensioning. The actual dimensioning of capacity concerns both the regular capacity, to cater for systematic variations, and safety capacity, to handle the stochastic variations. Despite the critical impact of these two types of variations, the support in the literature is limited in terms of formal methods for resource management based on dimensioning of capacity in general, and of safety capacity in particular. Capacity is one aspect of resources’ capabilities and as a point of departure for developing such methods, the two overarching challenges of form-place-time matching and capacity balancing are defined. These challenges are exploited to provide a holistic approach to the combination of capacity and the generic form, place and time transformations performed to create customer value. This approach requires alignment between these types of transformation to enable a homogenous perspective on different types of resources such as machines and stock shelves. Such transformations are performed over time and a discrete-time period-based approach requires that the intra-period transfers and inter-period variations are integrated. Finally, the preconditions for proactive and reactive control related to capacity required are outlined. A foundation for capacity dimensioning is then established based on capacity balancing, period transfers and flow control.