Design Realization/Detailed Design - Medical Device Design: Innovation from Concept to Market - page 182

3D model from CAD software

Brain creating “3D”
images

Image from 3D TV screen
or projection

Figure 8.19
Representation of a 3D visualization system.

Table 8.6: 6 σ Seven Wastes

Waste Description

1. Waste of overproduction What does overproduction mean to you?

2. Waste of waiting Time costs money.

3. Waste of transporting Are you moving things around too often?

4. Waste of inappropriate processing Only if necessary?

5. Waste of unnecessary inventory Stock on the shelf means less cash in the bank.

6. Waste of unnecessary motion Ergonomics and positioning - effort.

7. Waste of defects Defects cost money - not only replacement but also repair

contingency funds.

“New” Waste
7(a) Waste of making the wrong product Is your product valued?

7(b) Waste of untapped human potential Are you using all skills available?

7(c) Waste of inappropriate systems Are you using things just because you can?

7(d) Waste energy Are you wasting energy?

are pertinent to medical devices. Before we do so, let me introduce you to another useful 6 σ
tool: the seven wastes . If you use these as guides DFX becomes easier as the whole point of
DFX is to avoid waste. The seven wastes are a lovely tool to help you avoid “overdesigning”
your device. Table 8.6 introduces the seven wastes, and their newer siblings.

8.7.1 Design for Manufacture (DFM)
Very simply, your device has to be made. There may only be one; in which case DFM is not
important. However I am hoping that your device will be made in bulk. If this is the case DFM
is very important. The best way to consider DFM is to examine common failings that led to
its inception. Consider the component in Figure 8.20 . The designer produced a lovely CAD