The court was studied because of its involvement in a LEAA-sponsored delay-reduction project. The project changed the calendaring system, temporarily increased judicial staffing, and made other changes staggered over time to permit the analysis of separate effects. The 2,026 cases in the study constituted a random sample of felony complaints filed between April 1976 and March 1978. Case processing time was defined as the number of days between the defendant's initial court appearance and the disposition by dismissal, trial verdict, or plea. The analysis tested an explanatory model intended to be more fully specified and reflective of theory than previous models. The model included three types of case factors and three types of court factors. Most of the explanatory variables had the anticipated effects. Together, they explained case processing time well. The results showed that case processing time results from specific causes and not from a vague variable such as 'local legal culture.' The success of the Detroit reforms indicates their promise for use elsewhere. 3 Tables and 60 footnotes.