Ashby Theorems
From CasGroup
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There are a few laws and theorems about [[Basic_System_Theory|system theory]] proposed by | There are a few laws and theorems about [[Basic_System_Theory|system theory]] proposed by | ||
Cybernetics pioneer W. Ross Ashby. If is doubtful if they | Cybernetics pioneer W. Ross Ashby. If is doubtful if they | ||
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The principle has to be taken with care, because one can easy state | The principle has to be taken with care, because one can easy state | ||
| - | the contrary | + | the contrary "black box" principle that "even though a system is |
| - | not completely known, it can be managed effectively | + | not completely known, it can be managed effectively". It is obvious |
that one can control and regulate a system better if one understands | that one can control and regulate a system better if one understands | ||
it well, and a model can certainly ease understanding. | it well, and a model can certainly ease understanding. | ||
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Only variety in a system itself can successfully counter a variety of disturbances in the environment | Only variety in a system itself can successfully counter a variety of disturbances in the environment | ||
| - | This may seem obvious, because a flexible system with many options is of course better able to cope with change and changing conditions. In other words, | + | This may seem obvious, because a flexible system with many options is of course better able to cope with change and changing conditions. In other words, "the larger the variety of actions available to a control system, the larger the variety of perturbations it is able to compensate". |
| - | It is also clear that sufficient | + | It is also clear that sufficient "requisite variety" is already available in systems with a small numbers of elements, as soon as those elements can interact in arbitrary ways we get a combinatorial explosion. Thus the law might say nothing, but nevertheless there is some truth in it. |
