Prototype Phase

As the CE team works through various design iterations, portions of each design alternative will eventually be incorporated into the final design solution. In this process, sub-systems are tested and evaluated.


Translating voice of the customer (VOC) into an organization.

The Pugh matrix shown in Figure 4.7 was developed by Dr. Stuart Pugh to analyze various alternative systems and is a useful tool for this work because it helps to evaluate and prioritize CT characteristics of alternative designs during the prototyping phase. It begins with an evaluation of each alternative against the current baseline design. The best design alternative becomes the CE team’s new baseline and is progressively augmented using the features and functions from the other alternatives to develop a final optimized design.

The software application example is again shown in Figure 4.7 with four CT characteristics. Each alternative is evaluated against the prioritized CT characteristics. These CT characteristics were previously prioritized in the chapter using the paired-comparison and AHP methods shown in Figures 4.3 and 4.4. Using the prioritized CT characteristics listing, each alternative is compared against the current baseline design one at a time using


Prioritizing design alternatives using a Pugh matrix. CE = concurrent engineering.

a variety of testing data and other relevant information such as design drawings, process charts, capability studies, and design failure mode and effects analyses (DFMEA). If the alternative design is superior to the current design relative to a CT characteristic, it receives a +. If it is inferior, it receives a minus sign (-). If it is equivalent, it receives an S for similar. Additional +s and -s can also be used in the analysis. Eventually, these +s and -s are weighted using prioritization rankings, and a weighted total is calculated for each design alternative. The design alternative with the highest positive weighted total score is considered superior to the current baseline.

The goal is to incorporate the highest-ranking features and functions into the final design. As the final design emerges from this analysis, actual working models are built and tested to ensure they meet performance specifications. Engineering drawings, the BOM, test and inspection procedures, tooling, and other equipment as well as packaging specifications are almost finalized at this point. There may be minor changes to the final design after it has been evaluated during the pilot phase of the project.

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