To calculate the availability of multiple components, you must understand more equations: the serial equation and the parallel availability equation. One important thing to remember is that components can be system components (such as circuit boards) or network components (such as routers or switches).
You will use the serial availability equation whenever all the parts must work for the system (or network) to work. Equation 2-2 shows the serial availability equation.
Equation 2-2 Serial Availability Equation
In a serial system, if any component fails then the entire system fails. For example, ...