Organizations often experience difficulty in measuring the effects of automation-based process re-engineering. The autoregressive integrated moving average (ARIMA) methodology was used as a means to assess the effects of an automation-based process re-engineering of a purchasing process in a large regional hospital. Utilizing autoregressive statistical techniques, the automated purchasing process significantly affected productivity and performance both at the departmental and organizational levels. System implementation significantly reduced purchasing lead times, time to receive goods, and the time purchase orders stayed open. At the organizational level, values of issues per occupied bed increased, as did inventory turnover. The intervention analysis performed provided a means for management to assess the productivity improvements resulting from the re-engineering project. Provides additional insight concerning implementation research and measuring organizational and departmental effects of automation projects.