DTS 5701 deals with the complexities of large-scale systems. The large scale systems engineering framework defined here is "an extensible structure for describing a set of concepts, methods, technologies, and cultural changes necessary for a complete product design and manufacturing process" (CERN, 2001) of a large-scale system. The underlying foundations of LSSE are systems engineering, organizational learning and lean thinking.
According to INCOSE’s systems engineering handbook (Haskins, ed. 2006), the systems engineering perspective is based on systems thinking: "A systems thinker knows how systems fit into the larger context of day-to-day life, how they behave, and how to manage them. Systems thinking recognizes circular causation, where a variable is both the cause and the effect of another and recognizes the primacy of interrelationships and non-linear and organic thinking — a way of thinking where the primacy of the whole is acknowledged." Similarly the systems approach and systems engineering methodologies are used to understand the key issues in the planning, design and management of large-scale systems. Master planning and system architecting are essential components of LSSE. Systems engineering tools such as Analytic Hierarchy Process (AHP), engineering economy and the cost-benefit approach are part of the analysis of large-scale systems. In addition, risk (especially enterprise risk) and safety management is addressed in large-scale systems. Systems engineering helps to deal with the technical/ systems complexity of large-scale systems.
One of the most difficult tasks in large-scale systems is conceptualization/ planning and this is one of the main emphases of LSSE. It is similar to the conceptual stage of the life cycle stages identified in ISO/IEC 15288, whose purpose is to identify stakeholders’ needs, explore concepts and propose viable solutions. According to Ackoff (1974), "successful problem solving requires finding the right solution to the right problem. We fail more often because we solve the wrong problem than because we get the wrong solution to the right problem." Hitch (1960) said that ‘we often do not look at what should such systems do, but often at what do they do and what are they made of.’ This is made much worst for a wicked mess or large-scale system. For in dealing with such systems, as we try to formulate the problem to identify its root cause, we are also formulating the solution. Rittel and Webber (1973) also pointed out that the dilemmas of planning is in the searching for scientific bases for the planning of wicked problems. Planning is also made much more difficult with multiple stakeholders, for planning is a component of politics (Rittel and Webber, 1973). It is in the planning stage that people stake their claims to power and resources. Planning helps to create an agenda for determining the direction a system should take to achieve its desired future. It provides a framework for achieving competitive advantage. Perhaps more importantly, it allows all constituencies to participate and work together towards accomplishing goals and allows the system to set priorities. In many ways, LSSE is also a masterplanning or strategic planning process.
The systems engineering process is "iterative and supports learning and continuous improvement" (Haskins, ed., 2006). Similarly, learning is an important component of LSSE. The learning organization as espoused by Peter Senge (2006) provides the framework for learning as individuals and in teams. The learning organization emphasizes generative learning – expanding capabilities, creating (finding the opportunity before it becomes a problem), not just adaptive learning – responding to changing environment, business climate (Senge, 2006). It seeks to understand and meet the latent need of the customer – what customers might truly value, but have never experienced or would never think to ask for. One of the five disciplines of the learning organization is systems thinking and its importance to LSSE has already been described. Systems dynamics are tools used to analyze the complexities of large-scale systems for time and timing are important components in large-scale systems engineering. Time and delays cause boundaries to change, hence one cannot optimize a system all the time – robustness and resilience have to be built in. There is also a right time to introduce new concepts and to seek approvals as the right people has to be at the right time and place. Feedback is very important for organizations and people to learn. The other disciplines of the learning organization are shared vision – the practice of unearthing shared ‘pictures of the future’ that foster genuine commitment; personal mastery – the skill of continually clarifying and deepening our personal vision; mental models – the ability to unearth our internal pictures of the world, to scrutinize them, and to make them open to the influence of others and; team learning – the capacity to think together which is gained by mastering the practice of dialogue and discussion (Senge, 2006). Learning organization helps to deal with the behavioral complexity of large-scale systems.
Large scale systems engineering is not complete without understanding the organizations and the people that support them. Hence there is a need to understand the characteristics of different organizations and their ecosystems, especially the cultural changes required in the implementation of a large-scale system and the problems faced when different organizations interact with one another. Large-scale systems often have multiple stakeholders and the ability to manage them through dialogue is crucial to their successes.
One of the management principles in Toyota is to become a learning organization through relentless reflection (hansei) and continuous improvement (kaizen) (Liker, 2004). Hence, lean thinking (lean was pioneered by Toyota) seeks to maximize the work effort of a company through its people. It is therefore "a way of thinking" to adapt to change, eliminate waste, and continuously improve. It helps integration across domains, disciplines and organizations and introduces new ways to view processes through innovation and breaking paradigms (Womack, Jones and Roos, 1991). It also adopts a long-term philosophy, which is important in large-scale systems as they are usually of long duration. Lean thinking integrates technology, processes and people and support constant reflection and improvements.
Using the approaches and considerations mentioned in the preceding paragraphs, LSSE examines the goals of a system, its stakeholders, and its boundaries (political, social, environmental etc) and limitations including the complexities involved to understand the issues in planning, design and management of such large scale systems. In addition, the possible effects and unintended consequences are also considered. To do this, it draws upon some of the best practices from engineering, businesses management and political and social sciences.