LINKAGES AMONG DESIGN AND PROCESS FMEAS AND CONTROL PLAN | Six Sigma and Beyond: Design for Six Sigma, Volume VI

FMEAs are not islands unto themselves . They have continuity, and the information must be flowing throughout the design and process FMEAs as well as to the control plan. A typical linkage is shown in Figure 6.20.

Figure 6.20: FMEA linkages.

In addition to the control plan, the FMEA is also linked with robustness. To appreciate these linkages in FMEA, we must recall that design for six sigma (DFSS) must be a robust process. In fact, to see the linkages of this robustness we may begin with a P diagram (see Volume V) and identify its components . It turns out that the robustness in the FMEA usage is to make sure that the part, subsystem, or system is going to perform its intended function, in spite of problems in both manufacturing and environment. Of particular interest are the error states, control factors, and noise factors. Error states may help in identifying the failures, noise factors may help us in identifying causes, and control factors may help us in identifying the recommendations. The signal and response become the functions or the starting point of the FMEA.

The linkages then help generate the inputs and outputs of the FMEA. Typical inputs are:

System (concept) inputs

P diagram
Boundary diagram
Interface matrix
Potential design verification tests
Surrogate data for reliability and robustness considerations
Corporate requirements
Benchmarking results
Customer functionality in terms of engineering specifications
Regulatory requirements review

Design inputs

P diagram
Boundary diagram
Interface matrix
Customer functionality in terms of engineering specifications
Regulatory requirements review

Process inputs

P diagram
Process flow diagram
Special characteristics from the DFMEA
Process characteristics
Regulatory requirements review

Machinery inputs

P diagram
Boundary diagram
Interface matrix
Customer functionality in terms of engineering specifications
Regulatory requirements review