For sure. BriefBuilder is an excellent tool for describing and specifying complex systems (primarily buildings, but also other types of built infrastructure).
In line with the SE philosophy, BriefBuilder allows you to make different kinds of project decompositions (strategic, functional, technical, spatial, organizational) in support of the analysis, specification, design, and verification of systems.
It is important to note, however, that we don’t aim (nor pretend) to cover the entire SE process. Systems engineering is a very broad concept that covers all aspects and the entire life cycle of a system. As the SeBok wiki says:
“Systems engineering is a transdisciplinary approach and means to enable the realization of successful systems. Successful systems must satisfy the needs of its customers, users and other stakeholders.”
That is a pretty wide definition. The second part of the definition, however, is spot-on when talking about BriefBuilder. As it points out, successful systems are those that fulfill the needs of the stakeholders who will use, own, acquire and operate the system.
BriefBuilder is an excellent tool for capturing those needs and translating them into explicit, model-based requirements concerning the overall project and its parts. Subsequently, it allows you to analyse, verify, manage these requirements throughout the entire process, with the goal of creating highly effective systems that perform exactly as they should.