Systems of Systems (SoS) design is a complex process that involves, among other activities, the specification of system structure and requirements, the analysis of behavior and performance, and the exploration of the most appropriate system design solutions. Integration of these activities is advocated by Model-Based Systems Design (MBSD), where a core system model can be enriched with additional capabilities, such as performance analysis or decision-making. The Systems Modeling Language (SysML) is a standard language to utilize model-based design of SoS and create system models, specifying requirements and system constraints. In this work, we focus on integrating decision-making capabilities into SysML to enable system designers to explore alternative solutions that fit the requirements described in SysML. The system model is transformed to a decision model, whose results are automatically incorporated back into the system model. The proposed approach runs iteratively on any typical SysML model and facilitates the designer to explore alternative design solutions, minimizing the manual effort needed to achieve them. As a case study, the approach is applied in the design of a remote patient monitoring system, namely the Remote Elderly Monitoring System (REMS), where the designer decides on a system configuration that covers the needs of the patients.