Design-FMEA

Failure in the context here means that product performance does not meet requirements and is related back in the design FMEA to some component/character-istic being out of specified limits - a fault. The probability of occurrence of failure (O) caused by a fault can be expressed as ... 

The Conformability Matrix (see later for an example) primarily drives assessment of the variability effeets. The Conformability Matrix requires the deelaration of FMEA Severity Ratings and deseriptions of the likely failure mode(s). It is helpful in this respeet to have the results from a design FMEA for the produet. 

Following the eompletion of the variability risks table, a Conformability Matrix was produeed. This was used to relate the failure modes and their severity eoming out of the design FMEA to the results of the Component Manufaeturing Variability Risk Analysis. The portion of the matrix eoneerned with the moulded hub ean be found in Figure 2.34(d) and was eompleted using the Conformability Map. 

Determine reiiabiiity targets and faiiure modes taken from design FMEA inputs... 

Figure 3 Design FMEA for a bicycle rear brake lever...

Support design FMEAs with failure data wherever possible Input from the eustomer and suppliers is important Should be reviewed at regular stages... 

Figure 5 provides a blank table (eomplete with design revision seetion) used to perform a design FMEA. It forms a traeeable reeord of the design and its failure modes and assoeiated risks. 

There is one technique widely used in the automotive industry for detecting and analyzing potential nonconformities Failure Modes and Effects Analysis (FMEA). There are Design FMEAs and Process FMEAs. The technique is the same - it is only the focus that is different. As clause 4.14 addresses potential nonconformities, the subject of FMEAs is treated in Part 2 Chapter 14. 

The primary input data is product design data consisting of Design FMEA... 

Design FMEA where applicable Control plans... 

In both cases the Design FMEA and Process FMEA should be analyzed to reveal features that present a certain risk which can be contained by redesign with mistake-proofing features. 

Your first objective with axiomatic design is to make your design as independent as possible with reference to functionai requirements. After this you wouid make it as robust as possible, as per the information axiom, using such techniques as Robust Design (Technique 38), Design FMEA (Technique 40), and Mistake Proofing (Technique 49). 

To undertake robust design, you ll definitely need help from an experienced engineer or statistician familiar with this approach to testing and analysis. You ll also need to know how to apply several other techniques in this book including Performance and Perception Expectations (Technique 30), Axiomatic Design (Technique 31), Design FMEA (Technique 40), and Design of Experiments (Technique 50). 

Throughout the product or service life cycle, deterioration is likely to occur. Components wear out, materials become damaged or lose their effectiveness. In the service realm, human error and inconsistencies contribute to process variation and deterioration. To reduce the impact of these factors on performance, use Design FMEA (Technique 40) to flag areas that are susceptible to wear or failure, and then design your product or service to avoid or withstand deterioration as much as possible. 

A Design FMEA focuses on the interface of a new product, service, or solution with customers. A Process FMEA focuses on the behind-the-scenes steps that produce the product or enable the service provided. However, both FMEAs share a common format, approach, and interpretation. 

In constructing a Design FMEA, the language differs in a few key spots from a Process FMEA. For example, in a Process FMEA, the first column usually lists the process step under analysis. The first column of the Design FMEA, however, is a list of product or service components and the functions they re supposed to perform. 

Another area where a Design FMEA differs from a Process FMEA is in the controls and detection sections. In a Process FMEA, controls are production controls in a Design FMEA, controls are design controls. 

Prioritize the list of potential failure points to determine which ones are most worth your time and effort to prevent. One way to do this is using a Design FMEA (Technique 40) to calculate a Risk Priority Number (RPN), and then address issues with high RPNs as well as those with higher severity ratings. 

It takes many hours, even days, to complete a thorough Control Plan. This time can be minimized if you have already applied several techniques including Process MapA/alue Stream Map (Technique 45), Design FMEA (Technique 40), and Measurement Systems Analysis (Technique 47). 

A typical design FMEA is given in Fig. 13 for the alcohol example discussed earlier. The headings across the top of the FMEA define the types of information it requires. The DFSS team must evaluate the risk associated with failure of the CTQs. We discuss the functional requirement FMEA, but the same approach... 

Cycle-life testing Charge algorithm Control/sensor requirements End of life/aging criteria Design FMEA Emissions (Gas/hquid)... 

It is critical to spend early development time using failure mode and effects analysis (FMEA) and establishing a design plan that minimizes or eliminates the potential failure modes identified as part of the design FMEA. Using multiple tests to evaluate failure modes is also a key component to success. 

Potential Failure Mode and Effects Analysis in Design (Design FMEA) and Potential Failure Mode and Effects Analysis in Manufacturing and assembly Processes (Process FMEA) Reference Manual. Society of Automotive Engineers, 2000. 

System level design Team formation Senior tool designer need to participate in tool architecture assessment 3.1.4.1, 5.2, 7.1, 7.2 Design-FMEA Team assessment of tool design concept... 

Detail Design Organization need to support 2.1,2.2, 2.3, 2.5, Design-FMEA... 

THREE AND FOUR DIMENSIONAL NUMERICAL RISK SCORING SYSTEMS TABLE 4 Suggested Design FMEA Severity Evaluation Criteria ... 

The basic objective of FMEA/FMECA is early identification of catastrophic, critical and other potential failures so that these can be eliminated or mitigated through design and manufacturing process at the earliest possible time. There are three kinds of FMEA/FMECA, namely, functional FMEA/FMECA, design FMEA/FMECA (DFMEA/DFMECA), and process FMEA/FMECA (PFMEA/PFMECA) (see Clause... 

Types of FMEA/FMECA. (A) Relation amongst FMEA/EMECA types, (B) design FMEA/ FMECA concept, (C) process EMEA/FMECA concept, and (D) uses of EMEA/EMECA. 

SAE J1739 Potential failure mode and effects analysis in design (design FMEA) and potential failure mode and effects analysis in manufacturing and assembly processes (process FMEA) and effects analysis for machinery (machinery FMEA) ... 

PFMEA and relationship with DFMEA. (A) Process FMEA, (B) PFMEA relationship with design FMEA. 

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