This topic describes how two-terminal networks (source and sink) in a flow network are modeled. The capacity of the source is 100%. The capacity of the system is the capacity of the sink (terminal node), which is dependent on the set of working components. This is the capacity that is calculated. You can specify a capacity that is less than or equal to 100% for each component within a block. If a component is working, then its capacity is as specified. If the component is not working, then the capacity is zero.

The maximum possible capacity of a block is the sum of the capacities of the maximum possible working components (# of Components * Component Capacity). If the capacity of each component is 30%, then the maximum possible capacity of a 2-out-of-3 (parallel) system is 3 * 30% = 90%.

The capacity of a block or a module/system is always less than or equal to 100%. If the capacity of each component is 40%, then the maximum possible capacity of a 2-out-of-3 (parallel) system is min (100%, 3 * 40%) = 100%.

The capacity of a block is calculated based on the number of working components. If the number of working components is less than the minimum required for operation, then the capacity is zero. If the number of components is greater than or equal to the minimum required for operation, then the capacity is the minimum of either 100 or the sum of the capacities for all working components.

Suppose that the capacity of each component of a 2-out-of-3 (parallel) system is 40%. The capacity is 100% when all of the components are working. The capacity is 80% when two components are working. The capacity is 0% when only 1 or 0 components are working.

The capacity of a path with all in series is the minimum of the capacities of all the modules in the path. For example, if two blocks are in series and their capacities are 50% and 75%, then the capacity of this path is 50%.

The capacities of parallel blocks are the sums of the capacities of all blocks (provided the minimum required paths are working). If this sum is greater than 100%, then the capacity is 100%. If the minimum number of paths is not working, then the capacity is 0%.

Capacity is handled differently for a series blocks than for a block with series redundancy. The block with series redundancy is calculated as if it was an n-out-of-n parallel redundancy. You should carefully choose the correct configuration based on need.

The above rules are applied recursively to find the capacity of the system in a particular state.