A Fault Tree Analysis (FTA) diagram is a top-down, deductive failure analysis in which an undesired state of a system is analyzed using Boolean logic to combine a series of lower-level events. In the infectious control FTA, the fault or error happens when the ward failed to inform the porter, or the radiologist failed to inform the porter. The basic symbols that are used in the infectious control fault tree analysis diagram are grouped as events, gates, and transfer symbols. Events symbols here are used for primary events and intermediate events. The gate symbols describe the relationship between input and output events. And transfer symbols are used to connect the inputs and outputs of related fault trees.
