Abstract : This report attempts to provide a summary of major contributions obtained from supervised theses and my collaborations that have occurred over the last nine years. My research activities have been progressively shaped within the framework of Service Science with a focus on IT-enabled services. IT-enabled services are defined as “… organizational and socio-technical systems embedded in a complex and adaptive combination of people, businesses, technologies, and resources that interact with others.” These environments are digitally connected, collaborative, social-centric, ad-hoc, dynamic, distributed, and opened. As a matter of fact, IT-enabled services encourage introspection of behaviours and collaboration among people but they take on drastic challenges as how to design and implement services as socio-technical systems at a scale never before imagined (i.e., digital ecosystems). To tackle challenges related to IT-enabled services in collaborative, social-centric, ad-hoc, dynamic, and open environments, I have conducted my activities from two different, and yet complementary, research perspectives: service engineering and service computing. From a service engineering perspective, I have applied a systemic approach to tackle social aspects (e.g., people, businesses, organisational, social-based collaboration, etc.) from holistic and multi-disciplinary viewpoints by focusing on services as complex systems and developing a service design framework, including socio-technical views, a service reference model, data-driven collaboration processes, an incremental design method, requirement propagation, and system adaptability with feedback loops. From service computing, I have developed a “secured service-oriented aided infrastructure” to support IT-enabled service systems in ICT-facilitated environments and to access tangible/intangible resources in a trustworthy environment. Web services and SOA leverage IT-enabled services with an adaptable infrastructure to assemble reusable computational resources. In open, distributed, and socio-technical environments, I’ve tackled the challenge of designing secured SOA and identifying security risks and vulnerabilities at design time, and monitor security concerns at runtime by considering ambiguity, uncertainty and the randomness of the environment in which security threats occur. In this context, I have particularly focused on managing information security at the end-user level (e.g., user profiles, security preferences, quality of protection, …), the business level (e.g., security objectives, security policies, security treatment, …) and technical level, and encapsulating security mechanisms as (reusable) security services (i.e., security-as-a-service).