While there is plenty of leeway for interpretation or the meaning of a False Alarm (FA) as it may pertain to any particular industry or event, we will consider the FA to be the result of an incorrect indication of a “failure” as observed and reported by any sensing device. Furthermore, we will define that sensing device to be a Built-In-Test (BIT) or any other monitoring circuity or sensor. Before we jump ahead to learn about the significant what impact a well-executed diagnostic design process has on either FAs or System Aborts (SA), we will first examine BIT.
When the Start Up Built-In-Test (SBIT)reports back to the operator, or at the system or fielded product level, it is conveying the operational status, or health status of those specific subsystems that are involved in the proper functioning of the preliminary checkout of that equipment using the SBIT. Ultimately, we’ll need to examine precisely which functions are being examined by the SBIT or any other BIT, while the system or vehicle is operating in that particular state of operation, and as constrained by the functional test coverage by the specific SBIT.
The definition of a False Alarm, unfortunately is dependent upon your specific perspective. In a very general sense, it is the improper reporting of a failure to the operator of the equipment or system. In addressing the universe of possibilities that could compromise the proper reporting of a failure, DSI has conquered one specific cause and the primary contributor to the experience of False Alarms, which is the “Diagnostic-Induced” False Alarms, or more simply “Diagnostic False Alarms”.