Systematic fault isolation is the process of determining the cause and location of a problem within a system. This term most often refers to locating problems in a computer system, but the process can be used with any mechanical system.

Fault isolation may be built into the hardware using test circuits or by dividing operations into multiple components. These fault isolation tools allow each component to be monitored separately and the source of the error to be identified. Fault isolation tools can also include software that runs in different address spaces on hard drives or memory chips. Routines can be run in these isolated areas that pinpoint exactly where the system error is located.

In the absence of hardware or software isolation tools, the end user is able to perform fault isolation by stripping down the system to the bare minimum components needed to boot. Once the system has booted, individual components can be replaced until the error reappears. This process indicates exactly which component is at fault.

Systemic fault isolation can also be used on large data networks in the form of monitoring nodes at various locations while collecting traffic statistics. In this situation, the tools isolate where in the network the error occurred.