2.3.7 Sensitivity
A first step in the analysis or design of a system is the generation of models for the various elements in the system. The system characteristics are fixed when a finite number of constant parameters have been chosen. The values given to these parameters are called the nominal values, and the corresponding characteristics are called the nominal characteristics. The accuracy of the model depends on how closely these nominal parameter values approximate the actual parameter values, and how much these parameters deviate from the nominal values during the course of system operation.
The sensitivity of a system can be defined as a measure of the amount by which a system characteristic differs from its nominal value when one of its parameters differs from the number chosen as its nominal value. Consider a characteristic C that depends on a parameter p; that is, the mathematical model of the characteristic is C = C(p).