1998 Volume 84 Issue 8 Pages 598-602
Relationship between R&D resource input and R&D output is dynamic in nature. If this dynamics is understood well by researchers and engineers, it can help them plan and perform R&D effectively. There have been several proposed dynamic models, but they are intended for planning and analysis for managerial purposes and not necessarily describe and predict dynamics. It is shown in this paper that, based on simple hypotheses, a simple qualitative equation describing R&D dynamics can be obtained where basic variable describing technological competitiveness is taken as technological stock. The hypotheses are in the following: ( 1 ) Relative increment in technological stock (ΔS/S) is proportional to relative increment in cumulative resource input (ΔR/R). ( 2 ) Technological stock decreases with time at a constant rate. ( 3 ) There is a certain delay time for the resource input to produce result. The resulting equation is as follows:
S=R(t-γ)αe-βt
where α is an efficiency parameter, β is a decay or obsolescence parameter, and γ is delay time. For examples, this equation together with another minor hypothesis can describe well-known favorable effects of focused resource investment, switching of R&D subject, and top-heavy investment. The meanings of these parameters are also discussed in relation to the efficiency in R&D. The model can also be applied to various case studies of resource input and R&D output.
