An early warning security fence has three major components that each must perform in order for the system to perform. Their reliabilities are 0.58, 0.73, and 0.66. The reliability of this system is not very good. To improve reliability a backup component is added for each of the three components. These new components have the same reliability as the existing component, e.g., Component 1 reliability is 0.58, Component 1 Backup reliability is also 0.58