International Encyclopedia of Systems and Cybernetics

J. SUTHERLAND distinguishes the following types of systems:

"1) Deterministic: No significant relational or structural changes through time. State alterations are negligible.

"2) Moderately stochastic: Some significant changes in coefficient and parameter values, but invariant basic structural and relational properties.

"3) Severely stocastic: Significant relational and some structural (i.e.state-variable) changes through time, where relational changes are reasonably well contained and where structural changes are periodic (replicative) or are drawn from a limited population of state-variables (determinant array).

"4) Indeterminate: Significant structural change through time, such that the state-variables or major determinants cannot be preassigned except partially and probabilistically; both causal and structural properties either empirically inaccessible or unallegorizable; state-changes independent of prior states" (1973, p.146).

We should now (1992) add the chaotic type, which covers partially the three last types proposed by SUTHERLAND and introduces an appearently "stochastic determinism".

Another basic array of systems types, are, in the words of G. BROEKSTRA: "… the three levels of inquiry and description as distinguished by PRIGOGINE in physics: reversible classical or Newtonian mechanicial systems, irreversible equilibrium systems or systems near equilibrium as dealt with by classical thermodynamics, and nonequilibrium systems of the kind called "coherent, evolving systems" or dissipative structures" (1993, p.74).

E. JANTSCH (1975, p.69 hereafter) and later on B. BANATHY (1988), in a somewhat modified form, offered the following classification of human systems:

"Rigidly controlled systems pursue prescribed operational targets in prescribed ways for attaining them (Examples: factories, bureaucracies)

"Deterministic systems pursue prescribed operational targets but select between various ways and inputs for attaining them (Examples: vertically organized production lines in industry, bringing into play various sets of material and nonmaterial resources and in various sequences)

"Purposive systems pursue prescribed strategic goals or multigoal patterns, but select the corresponding operational targets (and the ways for attaining the latter) (Examples: Industry developing various and possible innovative product lines, or diversifying in products and services under function-oriented headings such as power generation, transmission, distribution and utilization, or food production, processing and distribution)

"Heuristic systems select their goals or multigoal patterns flexibly within the framework of a prescribed overall policy (Examples: Industry developing new functional foci such as environment, or education; universities setting up interdisciplinary programs)

"Purposeful systems formulate and select policies in the light of the long-range outcomes (system states) of their own and their environment's potential dynamics. (Examples: New institutional roles for business, e.g. planner for society, or for higher education, e.g., education for self-renewal; ecosystemic view of world dynamics and policies geared to stability rather than growth, etc.)

JANTSCH states: :The above classification is of general validity and may be applied to human systems of all sizes and scopes. (Ibid)

→"Systems (Basic classes of)".