To quantify the impact of ESSENCE on PH activities, an evaluation of epidemiology business processes pre-and post-ESSENCE was conducted. Staff time, computer programs/ systems utilized and computational steps were compared for tasks within three quantifiable areas: visualization creation, report production and activities during PH responses. Visualizations included production of a map, chart, table and epidemic curve for the same data. Report production tested the ability to create nontextual documents with multiple graphics. Conducting ad hoc ED surveillance was compared between ESSENCE and e-mail/telephone methods. QI reviews were compared between ESSENCE and Merlin Analysis Tools. The number of software or systems requiring training, which were replaced by ESSENCE, was reviewed. Computational steps included page clicks, exporting/importing data between systems and data management. Testing was conducted by a single reviewer proficient in current systems performing the task a single time to completion. Time and computational steps were measured from the initiation of a task to the completion of a usable product and then averaged across the three quantifiable areas.