beyond satisficing: design, trade offs and the rationality of engineering

S.L. Goldman © 2010Lehigh University

2010

Beyond Satisficing: Design, Trade

Offs and the Rationality of Engineering

Steven L. Goldman

Lehigh University

fPET, Colorado School of Mines

May 9, 2010


2010

The Techne of Philosophy and the Philosophy of Technology (1984)

The Social Captivity of Engineering

Philosophy, Engineering and Western Culture

A History of Engineering Education

Images of Science and Technology in Popular Film

No Innovation Without Representation: Technological Action in a Democratic Society

[3 White Papers and 4 mgmt.-technology books]

Why We Need a Philosophy of Engineering

Information, Technology and Society (2009)

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Technological Action

Understanding it is important, intellectually and practically:

Intellectually, for insight into Western culture.

Practically, for effective action policies.

Understanding the role of engineering in it is a necessary, but not a sufficient, condition for understanding technological action. Why?

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Engineering, Technology, and Design

Engineering is a necessary, but not a sufficient, condition for determining technological action.

The primary driver of technological action is the selective exploitation of technical knowledge on behalf of managerial agendas. The selection criteria reflect highly contingent commercial, political and social value judgments.

Their operation is manifest in the trade-off process within engineering design, but ubiquitous in engineering practice.

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Trade-Offs and the Rationality of Engineering

The operation of these value judgments is symptomatic of a willfulness that shapes engineering practice generically and is integral to engineering reasoning.

This willfulness is, I believe, irreducible, in spite of persistent efforts at eliminating it.

But will is, in the dominant Western intellectual tradition, antithetical to reason, thus irrational.

What, then, are we to make of the rationality of engineering?

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What is Engineering?

The invisibility of engineering’s nature.

The high visibility of everyday engineering practice and the invisibility of the design process.

The science-inflected character of modern engineering.

Western “high culture” prejudices, among them, for Reason and against “art”/know-how and action.

Canetti: “Among the most sinister phenomena of [Western] intellectual history is avoidance of the concrete”.

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Understanding Engineering

I want to do two things in this talk:

1. Distinguish engineering from science, in the process exposing a perennial conflict in Western culture.

2. Explore the relationship between engineering and the managerial decision making-dominated contexts within which it is practiced.

These two things are correlated and point to how understanding engineering better enables more effective science and technology policies.

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Understanding Engineering

First then, what is the relation between engineering and science? Between engineering knowledge and scientific knowledge?Do engineers possess knowledge, or only know-how?

Is know-how not knowledge?

What does “knowledge” mean? Who gets to decide that and on what grounds (no Universal Dictionary)?

“Knowledge” implicates “rationality”, “truth”, “reality”.

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Knowledge Hijacked!

By Plato, Aristotle, Rationalists, Idealists…

(From the Sophists, Skeptics, Pragmatists)Knowledge and belief differ in kind.

Knowledge is that about which we cannot be wrong.

Knowledge is not true belief, not even true belief “with an account”, so knowledge really is different!

The object of knowledge is the really Real (while the object of belief is experience).

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Sophist Counterpoint

Gorgias, Protagoras, Antiphon, Isocrates.

There are only beliefs, and their objects indeed are changeable experience.

Protagoras: Man as the measurer of all things, the source of all metrics that organize experience for effective action.

Plato: The Sophist, Phaedrus, Thaeatetus, Cratylus.

Aristotle: N. Ethics, Politics, Rhetoric.

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Sophist CounterpointPlato:

Gorgias ranks probability higher than truth.

Protagoras holds the truth of all statements to be context dependent.

Sophists:

Experience is not a “tertium quid” between Reality and mind.Knowledge as rhetorical, evolutionary.

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Plato vs. SophistsThe “battle of the (earth) giants and the (sky) gods

over the natures of being and of knowledge “has forever been joined”. Communing with the changeable/becoming via the body/senses vs. relating to “genuine”, unchanging, immaterial, being via the soul “through reasoning”.

The Sophists are enemies of the Friends of the Forms, who are the true philosophers, those who alone know.

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Knowledge vs. Know-HowScience is to Engineering as Plato is to the Sophists.

Science: universal, necessary, certain, timeless, abstract/theoretical, value-free, unique: Rational

Engineering: particular, contingent, probable, context-dependent, historical, concrete/practical, value-ridden, plural: Willful (hence not Rational).

Know-how is not knowledge, it only seems to be.

No room for know-how in the Platonic view and no felt need for it.

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Knowledge vs. Know-HowUnderstanding trumps action, theory trumps practice,

because reason and will are exclusive.

Plato: knowing trumps willing; incompetence of reason in “small tasks”.

Aristotle: theoretical and practical wisdom are distinct; action is not rational, “active” life is the best, yet the highest good for a rational being is reasoning about reasoning!

Principle of Sufficient Reason (Science) vs. Principle of Insufficient Reason (Engineering).

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PSR vs PIR

Rationality Will

Knowledge Experience

Truth Opinion

Certainty Probability

Objectivity Subjectivity

Universal Particular

Absolute Relative

Necessary Contingent

Deduction Induction

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PSR vs PIR

Abstract Concrete

Theory Practice

Understanding Doing

Unique Plural

Timeless Historical

Utopian Contextual

Philosophy Rhetoric

Substance Process

N.B. Only PSR has the fact-value problem!

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Plato Wins

What justification is there for Plato’s definition of “knowledge” with its consequences for “truth”, “rationality”, “reality”?Mathematics: exemplar of knowledge, truth, rationality

(deductive reasoning), reality (immutable/immaterial).

[Recall Protagoras on truth]

Implications for knowledge of nature? Impossible for Plato; possible for Aristotle at price of experience.

Challenge to founders of modern science.

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Plato and Modern Science

The elusive “scientific method”: how to use experience to make the unexperienced and unexperienceable reality visible to the mind.

Instruments as extensions of the mind.

Pursuing knowledge, however problematic that is.

Experience, experiment and a priori reasoning.

Demonstrating knowledge vs. know-how.

Theories vs. things; reasoning vs. doing.

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Sophists and Engineers

Engineers possess knowledge of the Sophist sort.Engineering reasoning operates under some PIR.

Knowledge as reasoned belief, inductive/experiential, exemplified by doing/know-how not by thinking/math.

Heirs to the Sophists: Skeptics, Pragmatists.Heroic, Tragic (Sophist: Protagoros and Gorgias on poetry

and aesthetics/harmony; Petroski), and Optimistic (Pragmatist: John Dewey) conceptions of knowledge.

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Engineering and Science

The science-engineering divide is rooted in profound divisions within Western culture.“Knowledge” and “rationality” are used equivocally in science and engineering.

(In truth, they are used equivocally within science!)

The contemporary overlap of science and engineering obscures a distinction that is of great intellectual and societal significance.

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Engineering and the Contexts of its Practice

I turn now to the relationship between engineering and managerial decision making.

This is driven by highly contingent value judgments.

It does not matter if the managers are engineers.

Technological action is always intentional: it always has a preconceived goal.

This constitutes a global value dimension of technological action that engineering inherits. (Recall fact-value problem.)

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Design and Trade-Offs

The values-driven character of managerial decision making is explicit in design, but it is implicit, at least, in all facets of engineering practice.

Design distinguishes engineering: no correct design; like composing/story-telling, not archaeology.

Engineering design is a process in which a problem is specified in enough detail that engineers can solve it.

Trade-offs lie at the heart of this process.

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The value judgments that drive the design process are constraints that take two forms;

They define the problems that engineers must solve as well as the terms of acceptable solutions.

In both cases, the constraints come from outside of engineering.

What to do and how to do it cannot be derived from engineering considerations alone, so the design problem is not itself a technical problem.

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It is in the design and trade-off processes that the selective exploitation of engineering knowledge is manifest via roles played by subjectivity, contingency, values, willfulness.

These are all integral to engineering reasoning, as they are not integral to scientific reasoning.

Everyone recognizes this situation, but it has elicited as a primary response treating it as a flaw in engineering that must be corrected.

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“Rationalizing” Engineering

There continue to be persistent efforts to tame the trade-off process by making it objective.

Rankine’s “compromised exactness” and efficiency: applying science scientifically (but not really!).

Herbert Simon’s “satisficing” and “aspiration goals”, but rationalizing design via optimization and decision theory/utility functions.

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“Rationalizing” Engineering

Rationalizing engineering by making design scientific:Operations Research and computer modeling, expert systems applications.

QFD, IDEF, Nam Suh’s Axiomatic System, Taguchi, DYM, Yoshikawa’s General Design Theory, Decision Matrix Techniques, Analytic Hierarchy Process, PERT, GRAI, GRAIL (out of Kaos), Analogy Based Design, Pugh Method, TRIZ (with Axiomatic System, ARIZ),….

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Engineering Revealed

The effort to rid engineering of willfulness is fundamentally misguided.

Tools that are at best useful, but not solutions.

Warnings from Schon, Box, Addis, Picon …

Arrow’s Impossibility Theorem.

The focus on needs is a red herring: wants drive technological action!

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Engineering Revealed

The effort obscures the essential character of engineering.

It blocks analysis of engineering as PIR-driven reasoning incorporating value judgments and willfulness.

How can reasoning, willfulness and value-judgments be integrated?

Still no formal theory of inductive logic: is one possible?

Still no objective assignment of Bayesian prior probabilities.

Hayek: “If information, preferences, means, then …”

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Science and Rational Action

Rational action is impossible on the Platonic view of knowledge/rationality.

By definition, will is excluded.

It’s worse than pointless to a theoretician/”spectator”.

Aristotle’s division of theoretical and practical wisdom.

Impotence of climate science in global warming debate.

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Engineering and Effective Action

Study engineering reasoning and technological action as they are for models of effective action.

Focus on trade-offs and the process of negotiating them with the external (managerial) and internal (“natural”) sources of constraints.

Explore the complex instrumentalism of engineering reasoning.

Expose the inevitable unpredictability of technological action and its implications for society.

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Engineering’s Rationality

Recognizing the distinctive “rationality” of engineering is consistent with the growing recognition, for example in economics, of the arbitrariness of the Platonic definitions.

There is a major piece missing from the Sophist-Pragmatist definitions: evaluating ends.

The stakes are high enough to justify the effort.

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