This chapter discusses the early decisions that affect the system and their impact on the alarm/access control database, and the many aspects of protection needed to secure a reliable database. The development of a security alarm and an access control system for a large facility requires tremendous effort. This effort starts with a list of functional requirements that are translated into a system of alarm and access points. A solidly designed system must be developed and carefully controlled through conception to acceptance. The proper steps that must be taken to ensure an effective security system may take months to complete. The system may incorporate thousands of alarm points and hundreds of badge readers, which will affect all employees in the facility on a daily basis. To assure minimal disruption, a database containing all the alarm points, badge readers, approved access levels, and badges must be accurate, well-maintained, and protected from corruption.