In modern supply chains, effective and efficient warehousing processes are important to fulfill customer orders within a minimum of time at lowest possible costs for customers (picking costs). To reach minimum picking costs, flexibility strategies in a warehouse are needed to handle the effects of short-term quantity and volume fluctuations. This article describes a flexibility concept to identify an optimal strategy (sequence of actions) for adapting cost intensive capacities in a warehouse in according with variability in quantity and volume of customer orders.