Reliability of AAL Systems Modeled as BPMN Business Processes

Abstract

The use of Ambient-Assisted Living (AAL) systems has been spreading across several countries, with the ultimate purpose of improving the quality of life of patients. These systems often reflect complex architectures including several components such as sensors, gateways, Information Systems or even actuators, as well as messaging and transmitting protocols. Failures in these systems can have severe impact on a monitored patient, and most components foresee some kind of compensation countermeasures to increase reliability. Nevertheless, these measures are often self-contained to a single component and do not address the overall AAL system reliability, disregarding precedent and successor activities and interactions that exist for each time a certain value is registered or a certain alert is triggered. In this paper, we propose a new approach to calculate the overall reliability of an AAL system. We take a Business Process Management (BPM) approach to model the activities and interactions between AAL components, using the Business Process Model and Notation (BPMN) standard. By extending the BPMN standard to include reliability information, we can derive the overall reliability of a certain AAL system. To prove this approach, we also present a reliability study considering scenarios with single and pairwise reliability variations of AAL system components. With this approach, healthcare managers can benefit from important overall reliability information of an AAL system, and better allocate the appropriate resources (including hardware or health care professionals) to improve responsiveness of care to patients.