  Society is challenging systems engineers by demanding ever more complex and
integrated systems. With the rise of cloud computing and systems-of-systems
(including cyber-physical systems) we are entering an era where mission
critical services and applications will be dependent upon
'coalitions-of-systems'. Coalitions-of-systems (CoS) are a class of system
similar to systems-of-systems but they differ in that they interact to further
overlapping self-interests rather than an overarching mission. Assessing the
sociotechnical risks associated with CoS is an open research question of
societal importance as existing risk analysis techniques typically focus on the
technical aspects of systems and ignore risks associated with coalition
partners reneging on responsibilities or leaving the coalition. We demonstrate
that a responsibility modeling based risk analysis approach enables the
identification of sociotechnical risks associated with CoS. The approach
identifies hazards and associated risks that may arise when relying upon a
coalition of human/organizational/technical agents to provision a service or
application. Through a case study of a proposed cloud IT infrastructure
migration we show how the technique identifies vulnerabilities that may arise
because of human, organizational or technical agents failing to discharge
responsibilities.
