7FM Design Root Cause Analysis with Single/Multi-Point Failure Analysis
Training Length - 2 Days
7FM methods solve design problems in hours rather than days or weeks. 7FM solves extremely complex problems in days or weeks rather than months or years. The conversation begins and ends with the function. A problem cannot be produced unless one or more functions misbehaves or is of poor quality. The function sequence, when it is good, produces good results. The first poor quality function produces a failure sequence. All functions in a sequence can quickly be compared to the problem or effect. Once the functional block diagram is created, all functions are laid flat and those involved with the problem are easy to see. The active, reactive, and passive functions are rationalized and challenged by the seven failure modes. All send information, send command request, or send energy functions from an E/E design can be easily understood. All locate, position, orient, and seal problems are extremely simple to solve. All structure failures are simple to solve. Causes are exposed and design parameters are changed. The problem is solved. Different problem behaviors relate directly to each of the seven failure modes which exposes direct and rational causes quickly.
Understanding the problem:
- The problem definition
- The Is/Is-not analysis
- The escape analysis
- The design/process comparison matrix
Documenting design architecture for:
- Super-system (vehicle, jet, train, ship, building etc.)
Defining the Functions
- Function categories: Active, reactive, passive, information, command request, and energy
- The temporal fault state analysis
- Identify the functions, in their sequence, which can produce or transfer the faults that create the problem.
- The function sequence from energy to the active function or to its static resolution.
- Degradation factors
Failure Modes/Fault States
- 7FM failure modes which directly link design parameters and degradations to the problem
- Linking the 7FM failure sequence from the first failure mode, through the failure sequence, to the problem
- Confirming function and fault state agreements
- Confirming requirements violation
- Understand how to study failures that do not follow the designed functional path (noise, odor, and thermal events)
- Using the matrix FMEA to prioritize causes (inputs, design elements, degradation factors to primary failure modes and effects.
- Function capability testing
- Fault injection testing
- Degradation testing
- Failure testing
- Basic statistical analysis and sequentially design experiments
- Recommended Design Changes, the solution selection matrix
- Tracking performance over time