This chapter discusses the maintenance and testing aspects. These functions are tied together, because testing often shows problems that must be addressed by repairing the equipment. Maintenance can be broken down into three areas: requested, preventive, and predictive. Requested maintenance is the approach that is taken by the vast majority of Security departments—that is, the “fail-and-fix” mode of maintenance. Preventive and predictive maintenance on security systems is not normally considered to be a cost effective approach; therefore, requested maintenance is the norm. Testing must be scheduled to find these problems. There are hard failures that are easy to find and requested maintenance is the best way to solve them. To address issues of a hardware failure, one must also consider examples of a camera that failed or a badge reader that stopped working. Testing is often overlooked in security centers because of the associated costs.