Progressive design

Early decisions made purely for process reasons often can lead to problems of safety and health (and environment) which require complex and often expensive solutions. It is far better to consider them early as the design progresses. Designs that avoid the need for hazardous materials, or use less of them, or use them at lower temperatures and pressures, or dilute them with inert materials will be inherently safe and will not require elaborate safety systems. ... 

A very successful progressive design approach for thrombin is to start from a small building block, known or expected to bind non-covalently in a precise position in the active site, and expand this by progressive addition of substituents. We have called such building blocks needles and have described the discovery of a thrombin-specific needle and its evolution to a full-blown thrombin inhibitor with the use of sequential X-ray structural analyses (see [28]). The details will not be repeated here. The inhibitor, napsagatran, 5 is shown in Fig. 7.5. 

The sirolimus-FKBP-12 complex does not affect calcineurin activity but rather inhibits a protein kinase that is a key enzyme in cell-cycle progression, designated mTOR. Inhibition of mTOR blocks cell-cycle progression at the Gj —> 5 phase transition. 

Sound user interface design requires engagement and close cooperation of representative users. In practice it is insufficient to simply hold a focus group to ask users what their requirements are. A better approach is to formally implement a user-centred design process. Here a small number of representative users are convened and comments are solicited on candidate designs. As the project progresses designers need to offer prototypes or test enviromnent for the subjects to try out the product. 

Progressive design specification with caution to avoid mistakes... 

In view of the present trend of miniaturization, commercial and domestic products are progressively designed to be smaller, lighter and more compact. As a result, Aere is a growing need for smaller and more complex shaped parts. Moreover, factory automation requires products to be designed with ease of assembly. This inevitably requires the number of parts per product to be reduced and hence, the deliberate redesign of parts with multiple functions. Individual components become more complex in shape. Due to these various reasons, it is evident that a cost effective method to produce small and complex precisitm metal components in high run volumes for custom parts markets is very much in demand. 

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