Chapter 8. Distributed control
Executive control concepts and mechanisms have evolved primarily in a highly centralized uniprocessor context, surrounded by the rather centralized (e.g., hierarchical) structures of nature and human society. At least partially as a consequence of this, there is currently some difficulty envisioning more “decentralized” control concepts and designing corresponding mechanisms. To help stimulate thought in this area, we present a conceptual model of the spectrum of control alternatives from maximally centralized to maximally decentralized. The model is not intended either to provide a quantitative measure of decentralization, or to ascribe attributes (e.g., “better”) to points in the spectrum—instead, its illumination should greatly facilitate the subsequent performance of these endeavors.
While decentralization of control is a logical matter, our centralized legacy includes important assumptions about communication characteristics which underly most control mechanisms if not also the concepts. These assumptions are frequently either not explicitly recognized, or ignored as being conceptually insignificant. This has resulted in control mechanisms originally intended for one communication environment (e.g., shared primary memory) being naively reimplemented in another (e.g., disjoint primary memories) with adverse consequences for their performance and even correctness. Thus, the search for new decentralized control concepts and mechanisms should carefully consider that the environment will often impose communication attributes which are unconventional in the executive control context.
KeywordsExecutive Control Control Space Signal Observability Primary Memory Control Decentralization
Unable to display preview. Download preview PDF.