What is one primary reason for components in a series system having low overall reliability?

In a series system, the overall reliability is heavily influenced by the requirement that every component must function correctly for the entire system to operate successfully. This "all-or-nothing" condition means that if any single component fails, it brings down the entire system.

This reliance on every component functioning flawlessly creates a compound effect on reliability. For example, even if several components have high individual reliability rates, the system's overall reliability can still be low if there are many components, as the likelihood of at least one component failing increases. Consequently, the more components in a series system, the lower the overall reliability becomes, owing to the cumulative risk associated with potential failures.

In contrast, while factors like the total number of components or the quality of materials can play a role in reliability, they do not directly highlight the fundamental issue of interconnected reliability that characterizes series systems. High individual component reliability alone does not necessarily indicate good system reliability due to the dependence on every component working.