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In this paper, we discuss the concept and properties of variance-based global sensitivity analysis, as an expansion of local sensitivity metrics (such as the degree of rate control), for modeling and design of catalytic reaction systems. Using an illustrative example and supporting theory, we show that: (i) for small variations in the parameters, global sensitivities are similar to local derivatives; (ii) for larger variations in the parameters (i.e., a larger parameter space), the global sensitivities provide a ranking of importance of parameters and impose a rigorous bound on the errors that arise from fixing one or more parameters to nominal values; and (iii) in general, the global sensitivities can be related to the extrema of local derivatives. We argue that the square root of the total global sensitivity of a parameter, computed by summing the global sensitivity of that parameter acting independently and in combination with others, is a “global” degree of rate control for catalytic systems.