1.1 Introduction
Objective for Engineering Decision-Making
During the last two decades, there has been growing awareness that our world only has
limited non-renewable natural resources such as energy and materials, but also limited
renewable resources like drinking water, clean air, etc.. This led the so-called Brundtland
Commission (1987) to the conclusion that a sustainable development is defined as a
development ''that meets the needs of the present without compromising the ability of future
generations to meet their own needs''. Sustainable decision-making is thus presently
understood as being based on a joint consideration of society, economy and environment. In
regard to environmental impacts, the immediate implications for the planning, design and
operation of civil engineering infrastructures are clear: Save energy, save non-renewable
resources and find out about recycling of building materials, do not pollute the air, water or
soil with toxic substances, save or even regain arable land and much more.
For civil engineering infrastructures and facilities in general, but not only for those, also the
financial aspect is of crucial importance. Civil engineering infrastructures are financed by the
public via taxes, public charges or other. In the end it is the individuals of society who pay
and, of course, also enjoy the benefits derived from their existence. However, seen in the light
of the conclusions of the Brundtland report the intergenerational equity must be accounted for.
Our generation must not leave the burden of maintenance or replacement of too short-lived
structures to future generations and it must not use more of the financial resources than are
really available. In this sense, civil engineering facilities should be optimal not only from a
technological point of view, but also from a sustainability point of view.
Societal Performance and Challenges
During the last century the societies of the industrialized world have undergone tremendous
developments on several fronts. As indicated when the term “the industrialized world” is
being used, development is commonly understood as being associated with technical progress
and this is surely also a good indicator; however, it is interesting also to consider other
indicators not directly related to technology. In Figure 1.1, as an example, the development of
the Gross Domestic Product (GDP) in Switzerland is illustrated for the period 1960-2002.