The rapid digitization of society is to a large extent driven by the interconnection of existing systems in order to co-ordinate their activities. This leads to systems-of-systems (SoS), where the parts more or less voluntarily co-operate for mutual benefits while keeping their autonomy. The term SoS started to become relevant some 20 years ago, and accelerated as a research area about 10 years ago. Although some people tend to take SoS as a synonym for large and complex systems, the research community has arrived at a fairly precise characterization of the term. In an SoS, the elements, or constituent systems, exhibit an operational and managerial independence, meaning that they can operate outside the SoS context, and have different owners. They choose to collaborate in order to achieve a common goal, manifested as an emergent property of the SoS, i.e. a property not existent in any of its parts in isolation. The field so far has been dominated by US researchers focusing on military and space applications. Key topics include architecture, communications, interoperability, modeling and simulation, and also a number of properties where dependability attributes such as safety play an important role. From its origins in the government driven sectors, SoS are now spreading to civilian and commercial usage. To investigate the needs and strategies for Sweden in relation to SoS, VINNOVA in late 2014 commissioned a consortium led by the Swedish Institute of Computer Science (SICS) to develop a research and innovation agenda for the area. The agenda project has included an industrial perspective captured in a series of workshops with practitioners, and also a research perspective. The latter was handled through an extensive research literature review, which indicated a poor representation of Scandinavia in the SoS research community. Also, a survey was sent to all relevant Swedish universities, research institutes, and funding agencies, and the result of this was somewhat contradictory. Many researchers are indeed working on topics related to SoS, but often use different terms for it, and publish at other venues than the SoS community. Given the large, but scattered, activity in the highly multidisciplinary SoS area, SICS and the Swedish Chapter of the International Council on Systems Engineering (INCOSE) decided to organize the 1st Scandinavian Workshop on the Engineering of Systems of Systems (SWESoS 2015). The primary purpose of the workshop was to create a meeting place for researchers and practitioners interested in SoS. The workshop was intended to be an informal event, focusing on presentation of results and ongoing research, to stimulate interaction among the researchers. This proceedings volume contains the extended abstracts of those presentations. In many cases, the presentations are based on work already published elsewhere, and the interested reader can find links to more material in each contribution. The scope of the workshop was all aspects related to SoS engineering. This included, but was not restricted to, the following topics when applied to systems of systems: Autonomous and cooperative systems; Business models, including software ecosystems; Case studies of applications in different domains; Control strategies; Communication; Dependability, robustness, and other quality attributes; Enterprise architecture; Governance; Interoperability; Modeling and simulation, including multi-agent systems; Service oriented architecture; Systems engineering methods; and Systems thinking. In total, 16 papers were submitted to the workshop, and 13 were accepted for presentation, whereas the remaining three were somewhat outside the core scope of the event.