This paper addresses some of the issues involved in defining and measuring the input side of a productivity model and in evaluating the efficiency of prosecutor and public defender agencies. The study examined three data files from Iowa, Kentucky, and Nebraska. Few persons argue with the need for measuring the performance of public service delivery systems, but actual implementation of performance measurement systems is often incomplete. These inadequacies are the result of some fundamental barriers impeding proper usage of performance measures. The barriers include little knowledge or acceptance of means to use of performance data and improper or time-consuming statistical reporting. Therefore, although the importance of productivity measurement is agreed to be a primary component of a performance system, in fact the knowledge and techniques for proper measurement are lacking. Prosecutors' and public defenders' offices do not lend themselves to measurement, which is perceived as a low priority in the first place. However, public service delivery systems can be more efficient. Measures of productivity in these offices show not only how effort is distributed but also the costs associated with various functions. Seven figures and 15 references are included.