The cash management of an automated teller machine (ATM) often combines a periodic review inventory policy with emergency orders, the latter according to a continuous review inventory policy. We present a simulation-based decision support system (DSS) that considers both regular (periodic) and emergency (continuous review) orders. This DSS was developed to assist an ATM's manager in the selection of the appropriate (regular) order and period sizes as well as the (emergency) reorder point under a given service level. The DSS was developed using the software Arena and integrates a Visual Basic for Applications (VBA) front-end that allows the user to incorporate fixed and variable ordering costs as well as demand and arrival rates updates.