Information systems as interventions: The case for outcomes-based evaluation

Intervation Analysis (IA) is a time series method developed to measure the effectiveness of interventions such as medical treatments. The authors contend that many managerial decisions, policies, and practices can usefully be thought of as interventions. Since many information systems (IS) are designed and implemented as a response to an observed problem in a regularly-collected data series (e.g. inventory costs, efficiency measures, financial ratios), they can be usefully thought of as interventions also. This paper investigates the application of IA to the evaluation of IS effectiveness. The data series that was the primary reason an IS had been implemented was analyzed using IA methods in several small businesses. This was accomplished by coding the implementation of the IS as either a step or pulse in a dummy variable. The results of the research indicate that IA is a very useful tool in conducting outcomes-based IS evaluation which goes beyond a perfunctory post-implementation audit. Furthermore, it was determined that operationally oriented IS proved to be the most effective.