system engineering is a set of principles, methods and techniques applied to all the tasks involved in all the life cycle stages of complex system
Systems engineering has its roots in three linked strands of thinking: the concepts of systems science, engineering and public policy problem resolution.
The first of these can be traced back to the work of von Bertalanffy (1968, pp. 8-15, 96-98) and others during the 1920s and 1930s but received a significant impetus when, in 1954, the Society for General Systems Theory was established at the annual meeting of the American Association for the Advancement of Science.
The society later changed its name to the Society for General Systems Research and launched an ambitious program:
The Society for General Systems Research was organized in 1954 to further the development of theoretical systems which are applicable to more than one of the traditional departments of knowledge. Major functions are to: (1) investigate the isomorphy of concepts, laws and models in various fields, and to help in useful transfers from one field to another; (2) encourage the development of adequate theoretical models in the fields which lack them; (3) minimize the duplication of theoretical effort in different fields; (4) promote the unity of science through improving communication among specialists.
(von Bertalanffy 1968, p. 13)
As this quotation suggests, the perspective of the Society for General Systems Research was scientific, but in parallel the use of systems as a technology for problem solving was developing rapidly.
In the 1930s the American pragmatic philosopher John Dewey proposed that there should be five phases or aspects of what he termed ‘reflective thought’:
• Suggestions - in which the mind leaps forward to possible solutions,
• An intellectualization of the difficulty or perplexity that has been felt, into a problem to be solved.
• An evaluation of the suggestions in turn as a leading idea or hypothesis, to guide observation and the collection of factual material,
• Elaborating the ideas through the application of reasoning,
• Testing the hypothesis by overt or imaginative action.
The five phases of Dewey's reflective thought (Dewey, 1933) exhibit the characteristics of systems methodologies.
The focus is on a problem that needs to be addressed. The approach involves investigation and data gathering to test the efficacy of different possible solutions.
Dewey's approach contains the two key elements of systems engineering: the advocacy of a method of enquiry and action, and the application of the method to the solution of real-world problems.
The application of mathematical techniques to military operations was pioneered in Britain during the Second World War (see Box 7) and became known by a variety of names (Hoos, 1972, p. 42). At the end of the war, the United States Air Force sponsored the application of those techniques and methods to problems of US national security.
Funds to investigate the effects of new weapons systems and for the exploration of defense policy issues were allocated to defense contractors. From one of these, the Lockheed Aircraft Corporation, the RAND (Research and Development) Corporation was spun off as a non-profit-making advisory consultancy that initially concentrated on issues of public policy.
As RAND's internet site puts it:
From its inception in the days following World War II, RAND has focused on the nation's most pressing policy problems. High-quality objective research on national security became the institution's first hallmark. In the 1960s, and in the same spirit, RAND began addressing major problems of domestic policy as well.
Today, RAND researchers operate on a uniquely broad front, assisting public policy makers at all levels, private sector leaders in many industries, and the public at large in efforts to strengthen the nation's economy, maintain its security, and improve its quality of life. They do so by analyzing choices and developments in many areas, including national defense, education and training, health care, criminal and civil justice, labor and population, science and technology, community development, international relations, and regional studies.
This quotation suggests three important features of the RAND approach. It had its origins in military systems and policy issues. It spread from this origin to be applied in a wide range of contexts. At the core of the RAND approach is the rational analysis of the choices that are available to decision-makers.
Gradually, the accepted name for this type of policy analysis became ‘systems analysis’, which an early practitioner denned as:… an inquiry to aid a decision-maker choose a course of action by systematically investigating his proper objectives, comparing quantitatively where possible the costs, effectiveness, and risks associated with the alternative policies or strategies for achieving them, and formulating additional alternatives if those examined are found wanting.(Quade, 1967)
You should now read the document "Box 7- The origins of systems analysis", in the section titled 'Extra reading materials'.
Systems analysis and its associated techniques were widely and enthusiastically adopted by public bodies and commercial companies alike. Central to the approach was the idea of rationality based on financial or operational modeling.
And it was this characteristic that caused systems analysis to come under critical attack from those who objected to what they regarded as the dilution of what should be a political process (Hoos, 1972; Lilienfeld, 1978) or who felt that rational analysis was not an adequate basis for decision-making.
Now read the following case studies:
• Fire Department Deployment Analysis - Modelling in Public Policy, which provides an example of an early RAND analysis carried out in an attempt to improve the deployment of resources.
• The Roskill Commission - Using Cost-Benefit Analysis for Public Policy, which discusses the problem associated with the application of rational methods to complex planning and decision-making processes through the example of the lengthy inquiry held during the 1970s and 1980s.
• Read the document "Case study 1 - Fire Department Deployment Analysis - Modelling in Public Policy",
• "Case study 2 - The Roskill Commission - Using Cost-Benefit Analysis for Public Policy", in the section titled 'Extra reading materials'.
As the example given in the London's Third Airport paper indicates, there were perceived problems associated with the use of systems analysis in public decision-making. These were as much to do with unrealistic expectations and the technological optimism of the time, as they were with faults in the approach.
The aim of the Roskill Commission had been to avoid ‘arbitrary and subjective judgements’ and it had attempted to include the ‘indirect impacts’ of the new airport. However, far from improving the acceptability of cost-benefit analysis, attempts to broaden its scope merely attracted the criticisms that the analysis had omitted important factors, that the broadening of scope had not gone far enough and that the valuations that had been incorporated into the process were wrong.
Attempts to answer these criticisms only made matters worse. In accepting that ‘the cost-benefit analysis could never include all the factors relevant to the decision’ the Commission was being realistic, but at the same time weakened the methodological basis of its decision. It provided the pretext for one of its number, Colin Buchanan, to dissent from its decision and, in doing so, opened the door to the political opposition that followed.
An important statement in the example in London's Third Airport is, ‘The forces of economic reason may have declared for Cublington, but the forces of environmental emotion were in favour only of Foulness, and they proved far stronger both in number and intensity.’ The mistake was in expecting, initially, that cost-benefit analysis would provide ‘the answer’. Then that it could be used as the basis for rational judgement, instead of regarding it as merely one of a number of inputs to a wider, essentially political, decision-making process.
The airport was never built at Maplin Sands or at any of the other sites considered by the Roskill Commission, but the controversy that focused on cost-benefit analysis called into question the use of systems analysis in matters of public policy. It was never to recover fully and, although the work of the RAND Corporation continues to this day, the glory days of systems analysis, in this sense of the term, were over.