Evaluation and Prediction of Circuit Performance by Statistical Techniques

A method is described for predicting circuit performance to the extent that it is dependent on part performance. The basis for the prediction is the performance of parts as measured at test points fixed by the part specifications. Implicit in this method is the assumption that the distribution of part performance at the test points can be predicted from consideration of the specifications. Such an assumption is necessary to any attempted prediction of this nature. An empirical equation giving circuit performance in terms of part performance as measured at the test points is assumed. The exact form of the equation is determined experimentally, by means of regression analysis of data consisting of sets of measurements of breadboard models of the circuit. The empirical equation is then used mathematically to calculate the distribution of the circuit performance from the assumed distributions of part performance. The method has been applied successfully to predict the laboratory performance of an ac amplifier and a telemetering oscillator. In principle, the method can be extended to the prediction of equipment or system performance.