An Introduction to Design Cybernetics

From Constrained Design to Designed Constraints to Constraint Reversal 1
FROM CONSTRAINED DESIGN TO DESIGNED
CONSTRAINTS TO CONSTRAINT REVERSAL
Thomas Fischer¹ and Laurence D. Richards² ¹Department of Architecture, Xi’an Jiaotong-Liverpool University, Suzhou, China, [e-mail]
²Indiana University East, Richmond, Indiana, USA [e-mail]
ABSTRACT:
This paper traces the changing notion of constraints in design along with the changing notion
of systems since the mid-20th century in the intersection of design theory and systems
theory. Taking a second-order cybernetic perspective, the paper develops constraints as
observer dependent, and it analyses conditions under which constraints tend to be beneficial
or detrimental. Ethical implications of constraints in design processes are established with
reference to system boundaries. Constraint-oriented design is discussed as an alternative to
goal-oriented design, and finally a method named constraint reversal is introduced as a
strategy of deliberate defiance of constraints to support design exploration.
1. INTRODUCTION: CONSTRAINT AS A SYSTEMS CONCEPT
Amongst the first to explicitly address the role of constraints in design was trained
mathematician and systems analyst Horst Rittel, professor and head of the Ulm School of
Design (HfG) and later professor at the University of California, Berkeley. Probably best
known for the distinction between “wicked” and “tame” problem that he proposed together
with Webber (Rittel and Webber 1973), Rittel was also amongst the first to apply a “systems”
approach to design. Rittel is thus an early representative of thinkers in the intersection
between design theory and systems theory. Second-order cybernetic design theory is a
contemporary development of this intersection, represented for example by Glanville (1999),
Jonas (2007) and Krippendorff (2006). In the following, cybernetics and the development of
the second-order cybernetic perspective will be taken as a vantage point from which to
examine the role of constraints in design.
2. CONSTRAINT AND VARIETY
Rittel frequently referred to cybernetician W. Ross Ashby (1956) and his work on variety.
Based on the notion of variety, Rittel proposed a fundamental division of design activities
that remained central to his teaching throughout his career (Protzen and Harris 2010 p.
118): Design entails “The generation of variety, and the reduction of variety” (ibid. p. 107).
Ashby’s work on variety in cybernetics gave prominence to the notion of constraint (Ashby
1956 p. 127ff.), which he defined as a “relation between two sets, [which] occurs when the
variety that exists under one condition is less than the variety that exists under another”
(ibid.). As an example Ashby offers (British) traffic lights, which are constrained so that only
four combinations of the on/off states of red, yellow, and green occur (one condition),
whereas eight such combinations would be available (other condition) if the three on/off
states could vary independently. Rittel then defines constraints as “certain values of the
decision variables or design variables [that] are excluded”. Using a spatial metaphor for
variety he continues: “[a]ll the knowledge the designer has, of a scientific or professional
character, can be plotted into the decision space as constraints, for example a ‘maximum
weight 5 tons’ constraint would cut off all solutions above that figure”.
Important distinctions have to be drawn between the traffic lights example and the decision
not to consider weights above some threshold in a design process. One is the distinction
between mechanisms and human decision making. Another is the distinction between
processes that are constrained from the outside and processes that are constrained from the
inside (Glanville 1997). This echoes Miller (1978 p. 659) who notes that “[c]ertain alternative
solutions are eliminated for an organization’s decider by constraints on it, either from inside
the system or from outside”. As will be shown below, the question of what resides within or

From Constrained Design to Designed Constraints to Constraint Reversal 2
outside of a system depends on the understanding of the term system, and, according to the
second-order cybernetic understanding, on the system’s observer. The traffic lights are a
mechanism which is constrained from the outside, by traffic rules and those who implement
traffic lights. The design decision to consider weights below 5 tons only is made by a human
acting within the decision process in question. The mechanism/human distinction and the
inside/outside distinction are related in as far as humans appear to be more capable than
mechanisms to engage appositely with what lies outside their systemic boundaries.
From positivist origins, both cybernetic theories and Rittel’s theories of design have evolved
over time. To develop a differentiated view of constraints in design, it is necessary to quickly
trace the changing understanding of the systems notion (including ‘systems boundary’, which
is essential to the inside/outside distinction drawn above) during the second half of the past
century.
3. SYSTEMS, OBSERVERS AND BOUNDARIES
As an early definition, Bertalanffy (1968 p. 38) describes the term system as a “(set) of
elements standing in interrelation”. This notion was taken up by early design researchers
(Gosling 1963 p. 24) who initially tended to apply the term system to outcomes of design,
i.e. to parts or components making up products. In this view, which is still encountered in
systems engineering and the engineering design fields, constraints are frequently used to
refer to limits imposed on variable elements of products, such as moving parts.
Others further differentiate Bertalanffy’s definition by recognizing the existence of systems in
contexts or environments, and the interaction of systems with their environments via inputs
and outputs that cross a given system’s boundaries. Further differentiations ascribe more
characteristics to systems, including teleological, i.e. goal-oriented (Churchman 1971 p. 42)
and self-perpetuating (Maturana and Varela 1987 p. 47) ones. Weinberg (2001 pp. 51ff.)
introduces a subjective, observer-dependent aspect by defining system as “[a] way of
looking at the world”. Rittel (1992 p. 59), analogously, states that a system “reflects
someone’s understanding of something” (“Ein System reflektiert jemandes Verständins von
etwas”).
Rittel’s recognition of systems as observer-dependent is one aspect of his proposal of a
second-generation of the systems approach, of design theory and of design methods, based
on his and others’ initial development, and later rejection of more positivist and more
determinist “first generation” ones (Cross 1984 pp. 317-327). This development is somewhat
analogous to the recognition of observer dependence (amongst other aspects) in cybernetics,
i.e. the development of second-order cybernetics. As an aside, it should be mentioned that
there are other notable analogies between Rittel’s move from first-generation to second-
generation design theories and the move from first order to second-order cybernetics.
Rittel’s description of the designerly condition as a “symmetry of ignorance” (Cross 1984 p.
325; Protzen and Harris 2010 p. 159), for example, resembles the symmetry of
conversations (Pask 1975) and the value of ignorance (besides knowing) noted in second-
order cybernetic design theory (Glanville 2004 pp. 423ff.).
In second-order cybernetics, systems are understood as bounded by the way observers
distinguish them. The systems notion, and along with it the systems boundary notion, thus
becomes subjective, corresponding to Spencer-Brown’s dictum “Draw a distinction” (Spencer-
Brown 1997). Brün (2004 p. 82), accordingly, states: “A system is not something that exists
objectively in space or time or anywhere. A system is the result of a look at a collection of
stipulated elements. Stipulated in that I say which elements I will look at.” Instead of
phrases like “defining a system” or “specifying a system” some second-order cyberneticians
hence use the phrase “looking a system”.
One may, for instance, choose to consider a person, say a child, as a system in the sense
that the child is an organism made up of organs (a set of elements standing in interrelation).
Alternatively, one may choose to recognize the child’s dependency on her mother, without
whose care and feeding the child would not survive. Now, the child and (at least aspects of)
the mother form a system. The observer has the freedom and responsibility to choose what
is relevant and considered as parts of a “looked” system. Analogously, a designer may

From Constrained Design to Designed Constraints to Constraint Reversal 3
choose to approach a design challenge at the level of an apartment building, or, realizing
some broader implications and dependencies, at the scale of an apartment block or a city
block. Rittel (1973) explains: “[e]very wicked problem can be considered to be a symptom of
another problem” (ibid. p. 165), and “[t]he choice of [a wicked problem's] explanation
determines the nature of the problem's resolution” (ibid. p. 166).
In this view, “system” is understood as whatever set of elements an observer considers as
acting together—for example, following a common goal (a teleological approach). Oftentimes,
systems we look (at) are bounded by physical skins, coatings, housings or some similar
demarcation of a boundary. The above-mentioned child, for example, has skin and clothing,
cells have membranes, birds’ eggs have shells, computers have cases, buildings have
façades, communities use buildings and so on. This can be explained by taking these systems
as having “evolved” or developed, or as having been given armor and structure to protect
them from destructive forces so as to maintain their coherence and integrity. The skin of a
child may likely coincide with the boundary an observer projects onto the child system seen
as an autonomous entity, because the forces that brought forth human skin, themselves
acting as observers, may have also approached the human body as an autonomous entity. If,
however, an observer chooses not to see the child as autonomous but as dependent on her
mother, then that observer is free to project a boundary which intersects with the boundaries
of the mother. This boundary now does not coincide with any physical hull. It is a projection
brought forth by an observer’s way of looking. This projected boundary, regardless of
whether it coincides with a physical boundary or not, is the systems boundary as approached
by second-order cybernetics. In this way, in the second-order cybernetic view, systems and
their boundaries are observer-dependent, and in principle independent from physical
configuration (Fischer 2012 pp. 679-680).
4. CONSTRAINED DESIGN AND DESIGNED CONSTRAINTS
By conceptualizing variety available to design activity as “design space” available for
exploration, Rittel uses the term constraint to describe what could be called “no-go zones”
within design spaces. Thereby, the systems notion is applied to the design process as
opposed to the design product.
We have thus arrived at two kinds of boundaries: One bounds elements of systems such as
the parties and influences acting in a design process, or components of a design product.
This kind of boundary delimits that which is considered as a system – for example, designers
in a design conversation (process) or components considered for integration (product). The
other bounds the degrees of freedom available for exploration. This kind of boundary delimits
the conceptual territories available for design processes to unfold.
While these two kinds of boundaries may be considered as distinct, Heylighen (1995)
proposes a very tight and abstract definition of the systems notion, which brings constraints,
variety and systems together in a simple relationship by defining “a system as a constraint
on variety” (ibid. p. 5). In this view, the two kinds of boundaries considered here appear less
distinct because both can be described with this definition. Moreover, the two kinds of
boundaries, even if viewed as distinct from each other, are likely to affect each other: No-go-
zones in design processes contribute to choices of elements and attributes of the product,
while considered product elements and attributes contribute to the establishment of no-go-
zones in the process. In both cases, however, variety is reduced, i.e. possibilities eliminated.
With constraints thus impinging on designerly freedom, the question arises whether they are
desirable or not, that is, whether they are beneficial or harmful. There is a far-reaching
consensus amongst designers and design theorists that, perhaps counter-intuitively, reduced
freedom is not necessarily harmful in design. Dorst (2003 p. 35) notes that design problems
can be rather open, and that constraints can help alleviate the resulting need for “a great
deal of conceptual juggling skills’’. Glanville (2013) states that “[reducing variety by way of
constraints] provides an advantage: many have experienced paralysis when faced with
seemingly limitless variety.” This echoes what painter van Gogh wrote in a letter to his
brother: “You don’t know how paralyzing it is, that stare from a blank canvas that says to
the painter you can’t do anything.” (de Leeuw 1996 p. 281). Total freedom (vast variety)
seems to offer unfavorable conditions for creative processes and its effects can be as