A capacity management system and method. The system includes a demand management module and a planning engine. The demand management module receives a demand comprising a request for a quantity of a device and a corresponding required date. The planning engine converts original planning buckets with varying bucket lengths into target planning buckets that have substantially identical bucket lengths. The planning engine further retrieves a cycle time of the device, and selects one of the target planning buckets accordingly. The planning engine also plans a capacity in the selected target planning bucket according to the quantity of the device.