A third focus in the pragmatic use of the systems approach rests in the attempt to
establish congruencies or “alignments” between different systems and to identify and
eliminate potential dysfunctions. Just as a sociotechnical approach to work design
emphasizes the importance of matching human and technical requirements, open-systems
theory more generally encourages a matching of the kind of subsystems illustrated in Exhibit
3.3. Here the principles of requisite variety, differentiation and integration, and other systems
ideas (discussed in Exhibit 3.2) can be brought into play. For example, the principle of
requisite variety is particularly important in designing control systems or for the management
of internal and external boundaries-for these must embrace the complexity of the phenomena
being controlled or managed to be effective. As we shall see later, the principle of
differentiation and integration is useful for organizing different kinds of tasks within the
same organization.