Reliability and Maintainability (R&M) issues are discussed which pertain to Fire Protection (FP) systems. Although R&M technology has been developed primarily for military and electronic systems, the philosophies and methodologies are applicable to the field of Fire Protection. To illustrate this, the reliability of a representative system for a high rise building is analyzed. Chance of failure and MTBF (Mean Time Between Failure) indices are calculated for a sub-set of equipment which delivers electrical power to a pump automatically. The system power depends upon redundant Diesel Generators (DG's) which back-up the electric Utility Line. Actual failure data is derived for each equipment. The results raise concern over the appreciable chance of failure of such systems. The case where only one back-up DG is used (typically) represents a condition which is worse. Several Maintainability concepts are presented. These include specification design requirements, fault detection, isolation, built-in test, automatic test equipment, and schemes utilizing Computer Management Systems for periodic exercise and monitoring of FP equipment. Overviews of several adaptable contemporary R&M programs are provided. These include the treatment of purely mechanical equipment. The authors highly recommend incorporation of modern R&M technology into the Science of Fire Safety. This should reduce the present lag in R&M applications for FP systems.