When the mapping from functional elements to components is one-to-one, each component implements one and only one function. Such components are therefore useful in any other applications where their associated functions occur.
Components of an artifact exhibiting an integral architecture would potentially be useful only in other artifacts containing the exact combination of functional elements, or parts of functional elements, implemented by the component.
A modular architecture also enables component interfaces to be identical across several products. Interfaces in modular architectures are decoupled—that is, a particular component will not have to change when surrounding components are changed.
Therefore, different sets of surrounding components, such as might occur in different applications, do not require different component interfaces. When interfaces are decoupled, an interface standard can be adopted and the same component can be used in a variety of settings.
— Design: Creation of Artifacts in Society by Karl Ulrich