P. van Bommel et al. (Eds.): PoEM 2010, LNBIP 68, pp. 145–161, 2010. © IFIP International Federation for Information Processing 2010 Adapting UML Activity Diagrams for Mobile Work Process Modelling: Experimental Comparison of Two Notation Alternatives Sundar Gopalakrishnan, John Krogstie, and Guttorm Sindre Department of Computer and Information Science Norwegian University of Science and Technology (NTNU) Sem Sælands Vei 7-9, 7491 Trondheim, Norway sundar@idi.ntnu.no, krogstie@idi.ntnu.no, guttorm.sindre@idi.ntnu.no Abstract. Even if geographical aspects such as location is included in several enterprise architecture frameworks [15], enterprise modelling notations seldom capture the "where" aspect, such as the location for performing some activity in a business process. However, for mobile information systems it is often relevant to model where something is supposed to take place. In a previous paper, we suggested some alternatives for small modifications to UML Activity Diagrams to address this, but then only comparing the alternatives analytically. In this paper, we report on a controlled experiment comparing the two most promising notations from the previous paper, one adding location to the activity diagrams by annotations, another indicating location by colour. The experiment investigated both the participants' opinions about the notations and their performance on some tasks requiring understanding of the models. For opinion there was no significant difference, but for task performance there was a significant difference in favour of the notation using colour. Keywords: Requirements specifications, mobile information systems, model- based development, UML activity diagram, enterprise modeling. 1 Introduction Mainstream process notations used in IS modelling tend to ignore the "where" aspect. For instance, BPMN [1] and UML activity diagrams [2] capture what (objects), how (sequence and parallelism of activities and decisions), who (swimlanes), when (time triggers and time events), and to a very limited extent why (e.g., how a decomposed activity diagram satisfies a higher level activity) - for the latter some extensions with process goals have also been suggested [3] - but not the location of the activities performed. With a view on traditional information systems, where work is performed by people sitting in their offices using desktop computers, the neglect of physical location is understandable - it is much more important whether a task is performed by the purchasing or salary department than whether the worker is sitting in office 221 or 325. Hence the usage of swimlanes to denote organizational placement rather than geographical placement is easily justified.