We present an innovative conceptual framework to guide experimentation, testing and evaluation of complex systems-of-systems (SoS) in the context of crisis management, safety and security applications. The framework allows to account for structural and functional aspects of the SoS, including cross cutting factors (e.g., cost, legal and ethical factors). It provides a means to model in a coherent way all the elements of the SoS, regardless of their technological or human nature. Moreover, it accounts for the physical and cognitive aspects that characterize the different elements of a SoS in a uniform way. This work presents the concepts underlying the proposed framework structure, introduces further development goals and describes how the framework has been used to guide the outcome assessment of a project aiming at developing an advanced information fusion system that exploits maritime unmanned systems capabilities for improved maritime situational awareness.