This definition appears very rarely
Advanced Base Functional Component System (ABFCS) During World War II the Navy had faced base building problems and had developed the Advanced Base Functional Component System (ABFCS). During the buildup in Vietnam, the Navy used many elements of that system. The Da Nang hospital was constructed almost entirely of quonset huts, which make up a large part of the system. However, the standards of the ABFCS were quite austere.