This dissertation considers three broad issues which emerge from the sustainability discourse. First is the nature of the discourse itself, particularly the underlying philosophical positions which are represented. Second, is the nature of the highly complex types of problem which the discourse exposes. And third is whether the engineering profession, as it is practised currently, is adequate to deal with such problems.
The sustainability discourse exposes two distinct, fundamentally irreconcilable philosophical positions. The first, “sustainable development”, considers humanity to be privileged in relation to all other species and ecosystems. It is only incumbent upon us to look after the environment to the extent to which it is in our interests to do so. The second, “sustainability”, sees humanity as having no special moral privilege and recognises the moral status of other species, ecosystems, and even wilderness areas. Thus, sustainability imposes upon us a moral obligation to take their status into account and not to degrade or to destroy them.
These two conflicting positions give rise to extremely complex problems. An innovative taxonomy of problem complexity has been developed which identifies three broad categories of problem. Of particular interest in this dissertation is the most complex of these, referred to here as the Type 3 problem. The Type 3 problem recognises the systemic complexity of the problem situation but also includes differences of the domain of interests as a fundamental, constituent part of the problem itself. Hence, established systems analysis techniques and reductionist approaches do not work. The domain of interests will typically have disparate ideas and positions, which may be entirely irreconcilable.
The dissertation explores the development of philosophy of science, particularly in the last 70 years. It is noted that, unlike the philosophy of science, the philosophy of engineering has not been influenced by developments of critical theory, cultural theory, and postmodernism, which have had significant impact in late 20th-century Western society. This is seen as a constraint on the practice of engineering. Thus, a set of philosophical principles for sustainable engineering practice is developed. Such a change in the philosophy underlying the practice of engineering is seen as necessary if engineers are to engage with and contribute to the resolution of Type 3 problems.
Two particular challenges must be overcome, if Type 3 problems are to be satisfactorily resolved. First, issues of belief, values, and morals are central to this problem type and must be included in problem consideration. And second, the problem situation is usually so complex that it challenges the capacity of human cognition to deal with it. Consequently, extensive consideration is given to cognitive and behavioural psychology, in particular to choice, judgement and decision-making in uncertainty.
A novel problem-structuring approach is developed on three levels. A set philosophical foundation is established; a theoretical framework, based on general systems theory and established behavioural and cognitive psychological theory, is devised; and a set of tools is proposed to model Type 3 complex problems as a dynamic systems. The approach is different to other systems approaches, in that it enables qualitative exploration of the system to plausible, hypothetical disturbances.
The problem-structuring approach is applied in a case study, which relates to the development of a water subsystem for a major metropolis (Sydney, Australia). The technique is also used to critique existing infrastructure planning processes and to propose an alternative approach.