TIME LAG 1)2)
A delay in the transmission of effects between different components or subsystems in a system.
Time lags are basically caused:
- by operation lags, corresponding to the time a component or subsystem needs to process some specific input;
- by transport lags, "which arise from the delays occasioned by the moving of materials or other stimuli from the neighborhood of the components which produce them to the neighborhood of the components to which they serve as inputs" (W.R. ASHBY, 1960, p.39).
- It may also represent the duration needed for the exhaust of some systems buffer reserve which normally compensates external noxious impacts. A good example is the slow acidification of many lakes, whose effects become obvious many years after the onset of the acidifying influences (W. STIGLIANI & W. SALOMON, 1993, p.38). This last type of time lag is a very dangerous phenomenon, because long term trends may remain unperceived for very long time and accumulate potentially massive threats, which may be irreversible when they become clearly visible.
Time lags become of cardinal importance in systems with three or more independent initial conditions. As these are generally quite unequal, they reduce, up to a point, the general coherence of the system and introduce local determinisms disconnecting partly and for the duration of the time lag the components or subsystems from the rest of the system. This is one of the roots of chaotic behavior.
The above described condition is proper to any distributed system, be it a human social system, or a group of interactive robots or computers. In J.P. VERJUS words, for example: "In a distributed information system, there are always transmission time-lags, which impede that some message emitted from somewhere can be known immediately in other places. As a result, at any moment and any place, it is merely possible to know approximately the state of other places. It is even possible that… two different events taking place within the system could be received in different sequential order in various different places" (1988, p.1390).
Time lags, which are inherent in complex systems, play havoc with predictability and sometimes with design. They may seriously disorganize systems, because some effects may remain hidden for long time and become irreversible before they are observed. As an example, K. KRIPPENDORFF writes: "In modern society, institutional developments tend to lag behind changes in technology, causing many social problems… and conflicts" (1986, p.42). He could have added "and many ecological problems".
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To cite this page, please use the following information:
Bertalanffy Center for the Study of Systems Science (2020). Title of the entry. In Charles François (Ed.), International Encyclopedia of Systems and Cybernetics (2). Retrieved from www.systemspedia.org/[full/url]
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