Comparing Actual Practice and User Manuals: A Case Study Based on Programmable Infusion Pumps

We report on a case study investigating current practice in the use of a programmable infusion pump. We start by formalising an existing description of the procedure followed by nurses for setting up a commercial infusion pump obtained via observation and interview. We then compare and contrast this procedure with a formal description of the sequence of actions reported in the pump’s user manual. Mismatches were validated by a training manager. The aim of this comparison is to point out how minor mismatches between the two descriptions can be used to reveal major safety issues. Our contributions are: first, we analyse a realworld system and show the importance of having a clear and consistent specification of the procedures; second, we show how a graph-based notation can be conveniently used as the basis for building non-ambiguous and intuitive specifications in higher-order logic. We argue that this can provide support to an investigator when building a description of actual practice in that it can help focus attention on areas to observe more closely and on questions to ask to understand why procedures, as followed, are the way they are.