Fault assessment using fractional failure rates

A method for determining a fractional failure rate in an electronic system, the method comprising:

• identifying a fault in the electronic system;
• determining a list of circuit connections for signals associated with the fault;
• determining a component fractional failure rate for a component associated with the fault wherein determining the component fractional failure rate includes calculating a ratio of a number of circuit connections associated with the fault to a number of active pins on the component;
• determining a circuit carrier fractional failure rate associated with the fault, wherein the circuit carrier failure rate is amortized based on a number of components mounted to a circuit carrier in the electronic system;
• and
• determining a fault fractional failure rate, wherein the fault fractional failure rate is determined by adding the component fractional failure rate and the circuit carrier fractional failure, wherein the fault fractional failure rate indicates a percentage of a system failure rate to which the fault contributes.

A computer system comprising:

• a processor;
• a carrier medium coupled to the processor, wherein the carrier medium is configured to store instructions that, when executed by the processor:
• identify a fault in the electronic system;
• determining a list of circuit connections for signals associated with the fault;
• determining a component fractional failure rate for a component associated with the fault, wherein determining the component fractional failure rate includes calculating a ratio of a number of circuit connections associated with the fault to a number of active pins on the component;
• determining a circuit carrier fractional failure rate associated with the fault, wherein the circuit carrier failure rate is amortized based on a number of components mounted to a circuit carrier in the electronic system;
• and
• determining a fault fractional failure rate, wherein the fault fractional failure rate is determined by adding the component fractional failure rate and the circuit carrier fractional failure, wherein the fault fractional failure rate indicates a percentage of a system failure rate to which the fault contributes.

A method for determining a fractional failure rate in an electronic system, the method comprising:

• identifying a fault in the electronic system;
• determining a list of signal connections associated with the fault, wherein the signal connections are present on a first component of a first unit and a second component of a second unit;
• determining a unit fractional failure rate for the first unit;
• determining a unit fractional failure rate for the second unit;
• unit, wherein the unit fractional rate for each of the first and second units includes a component fractional failure rate, a connector fractional failure rate, and a circuit carrier fractional failure rate, and wherein the circuit carrier fractional failure rate for the first unit is based on an inverse of a number of active components mounted to a circuit carrier of the first unit and wherein the circuit carrier fractional failure rated for the second unit is based on an inverse of a number of active components mounted to a circuit carrier of the second unit;
• adding the fractional failure rate for the first unit and the fractional failure rate for the second unit to obtain a system fractional failure rate.

A method for determining a fractional failure rate in an electronic system, the method comprising:

• identifying a fault in the electronic system;
• determining a list of signal connections associated with the fault, wherein the signal connections are present on a first component of a first unit and a second component of a second unit;
• determining a unit fractional failure rate for the first unit;
• determining a unit fractional failure rate for the second unit;
• adding the fractional failure rate for the first unit and the fractional failure rate for the second unit to obtain a system fractional failure rate;
• and
• calculating a cause probability for the first unit and a cause probability for the second unit, wherein the cause probability for an individual unit is 100% times the ratio of the unit fractional failure rate to the total fractional failure rate.