When a diagram node (representing a Design element or Process) is selected, the table in the lower part of the screen displays corresponding Failure Modes and Causes.

The lower FMEA table shows the following:

Potential Failure Mode: Failure Modes are sometimes described as categories of failure. A potential Failure Mode describes the way in which a product or process could fail to perform its desired function (design intent or performance requirements) as described by the needs, wants, and expectations of internal and external Customers. Each process/element may have an unlimited number of failure modes, and each failure mode may have an unlimited number of corresponding causes of the failure.

As noted in the AIAG Potential FMEA Reference Manual, a potential failure mode is defined as the manner in which a component, subsystem, or system could potentially fail to meet the design intent. The potential failure mode could also be the cause of a potential failure mode in a higher-level subsystem or system, or be the effect of a potential failure mode in a lower level component. A recommended starting point is a review of past items that have “gone wrong”, concern reports and group “brainstorming”. Potential failure modes that could only occur under certain operating conditions, such as hot, cold, dry or dusty weather should also be considered.

Effect of Failure: An Effect is an adverse consequence that the Customer might experience. The Customer could be the next operation, subsequent operations, or the end user. State clearly if the failure mode could impact safety or non-compliance to regulations. The effect should always be stated in terms of the specific system, subsystem, or component being analyzed. Potential effects of failure are defined as the effects of the failure mode on function as perceived by the customer.

Severity: Severity is an assessment of how serious the Effect of the potential Failure Mode is on the Customer (value of the most serious effect). Explanation of Severity values can be found in the library (press the <….> button near the Severity field).

Enter the following Cause of Failure data:

Potential Cause of Failure: A Cause is the means by which a particular element of the design or process results in a Failure Mode. Enter every Potential Cause for Failure Mode. Potential cause of failure is defined as an indication of design weakness, the consequence of which is the failure mode. The designer should assess the occurrence and detection of each cause, as well as the severity of each end effect.

Occurrence: Occurrence is an assessment of the likelihood that a particular Cause will happen and result in the Failure Mode during the intended life and use of the product. An explanation of Occurrence values may be found in the library (press the <….> button near the Occurrence field).

Controls: Controls (Design and Process) are the mechanisms that prevent the Cause of the Failure Mode from occurring, or which detect the failure before it reaches the Customer.

Detection: Detection is an assessment of the likelihood that the Current Controls (Design and Process) will detect the Failure Mode, thus preventing it from reaching the Customer. An explanation of Detection values may be found in the library (press the <….> button near the Detection field).

RPN: (Automatically calculated, you do not have to enter it.) The Risk Priority Number is a mathematical product of the numerical Severity, Occurrence and Detection ratings. RPN = (S) * (O) * (D). This number is used to place priority on items than require additional quality planning. FMEA automatically calculates risk priority numbers.

Actions Taken: Data about the corrective actions, implemented to improve RPN.

Occurrence (resulting): Improved Occurrence value after the implementation of “Taken Actions”.

Detection (resulting): Improved Detection value after the implementation of “Taken Actions”.

RPN (resulting): Improved RPN value after the implementation of “Taken Actions”. FMEA automatically calculates resulting risk priority numbers.