To compute the best match between requirements and capabilities implies that a capability profile can be compared to an application requirement profile. The capability profile indicates the available technology through commercial products as well as through pre-industrial laboratory prototypes (the last stage of the prototyping process). It exhibits what can be done. The application requirement profile indicates the technology needed to satisfactorily meet the user expectations . It expresses what should be done. Fitting capabilities against requirements can be illustrated as in Figure 2.2.
Of course the issue is more complex and many dimensions are needed to represent the fitting of capabilities against requirements. Although in many cases the relevant factors can be atomised as few major parameters which are called dimensions of difficulty [Moore (1994a)]. If we imagine this as a simple three dimensional space one may have the two representations shown in Figure 2.3.
Figure 2.2: Capabilities versus requirements
Figure 2.3: Specifications versus capabilities
The application developer should look for the best fit between his application requirements and the capabilities of available technologies. Obviously some of his requirements may not be satisfied. Optimisation criteria should be considered in order to evaluate acceptable shortfalls in some dimensions against the improvements gained in others. The compromise he has to accept implies adjustments of the requirements, keeping in mind a bottom-line global performance.
Moore expressed this suitability of a system for a particular application with a diagram that is simplified in Figure 2.4.
Figure 2.4: Technology specifications versus application requirements