Evolving Commitments for Self-Adaptive Socio-Technical Systems

Socio-technical systems (STSs) consist of human, hardware and software agents that work in tandem to fulfill stakeholder requirements. A specification for an STS consists of a set of (social) commitments among participating agents that serve as a contract among them. However, by their very nature, STSs are open, dynamic and continuously evolving along with their environments. To ensure that such systems continue to satisfy their requirements, the agents that comprise an STS must continuously adapt their behaviors to take into account risks and opportunities that arise at runtime. This paper presents a decision-theoretic self-adaptation framework that proposes candidate adaptation strategies for participating agents. These strategies are implementable by reconfiguration of plans or even changes in contractual commitments among agents. The adaptation procedure involves negotiating commitment changes and possible compensations to/from creditor agents. To evaluate the proposal, the paper also presents the results of an experimental study with a simulated STS, which confirms that success rates for achieving stakeholder goals and overall tradeoff utility can be improved significantly by incorporating evolving commitments to support STS adaptation.