Understanding ComplexEngineered Systems A Presentation for the Royal United Services Institute Given by Professor David Stupples 10th September 2008
Today’s talk • Definition of complexity • Dimensions of complexity • Examples of complex systems • What were the outcomes • Why these outcomes • Designing complex systems • Whole systems design
A complex system is a system formed out of many components whose behaviour is emergent, that is, the behaviour of the system cannot be simply inferred from the behaviour of its components. The amount of information necessary to describe the behaviour of such a system is a measure of its complexity. (Yaneer Bar-Yam) • A hierarchical system is a system that is composed of interrelated sub-systems being, in turn hierarchic in structure until we reach some lowest level of elementary sub-system. It is the hierarchical interrelationships that gives rise to the complex emergent behaviour. • (Herbert A Simon)
Dimensions of complexity • Systems complexity can be broadly categorised: • Engineering complexity • Technology complexity • Project complexity • Operational complexity It is acknowledged that most complex engineering projects are ‘multi-dimensional’ in nature, and therefore require a systematic approach to cope with the complexity involved.
Complexity involved Engineering complexity – diverting the Yangtze river during build, management of flooding in the lower Yangtze, long distance power distribution and line loss, building of locks causing minimum economic disruption. Project complexity - largest hydro-electric generator (22 GWe by 2011), cost $25bn, project duration (20 years from design), management of over 10,000 contracts and over 1000 contractors, relocating 140,000 people, etc. Operational complexity - loss of river flushing effect (pollution), lack of silt deposit (coastal erosion) and sinking coastal areas. loss of 13,000 farms, loss of forestation, change to rural environment
Complexity involved Engineering complexity included – fitting of the largest gas turbines to date, using Catia 3D design for the first time, use of a full glass cockpit for the first time, use of fully configurable avionics using fibre optics, first Boeing large commercial jet with fly-by-wire. Technology complexity included – use of significant carbon fibre panels, revolutionary wing design and proof of fly-by-wire software. Project complexity – design and build with more than 20 countries involved, more than 40 major contractors participating, tightly controlled budgets for cost and weight, multi company/country use of Catia, Boeing internal politics. Operational complexity – all airline customers involved in the design.
Complexity involved Engineering complexity – building and commissioning a major terminal within a working airport adjacent to one of Europe’s busiest highways, relocating one of London’s major sewage processing plants and diverting waterways. Technology complexity – developing and implementing one of the world’s most sophisticated baggage handing systems and passenger information systems. Project complexity – developing and managing a sophisticated and efficient contracting strategy together with effective contractor management to contain cost and risk, and to maintain an exacting time schedule. Operational complexity – transition from a project to operations with minimum disruption.
Complexity involved Engineering complexity – designing and implementing probably the world’s second largest and most complex computing system and transiting from the existing system whilst fully operational. Technology complexity – designing and implementing new cutting-edge infrastructure to support the future needs of signals intelligence. Project complexity – managing a PFI contract for the new building and numerous technical contracts to deliver the new facility on time and to budget. Operational complexity – the transition from existing operations on one site to new operations on the new site without losing a single moment of operational capability, especially during 9/11, 7/7 (and subsequent terrorist activity), Afghanistan and Iraq military operations.
Project outcomes • Three Gorges Dam – expected to be delivered on time and to budget delivering 22 GWe but environmentally very damaging with substantial negative impact on rural economics caused by operational complexity. • Boeing 777 – technically and operationally successful, but will not deliver the level of profit planned owing to the project complexity. • LHR Terminal 5 – very successful engineering project but suffered substantial transition problems from project status to operations. • GCHQ – fully successful in all respects.
Why is this? • Government influence or pressure to ignore the wider system issues (China) – successful project and facility but not environmentally acceptable • Shareholder value or profits were paramount (BAA) – successful project but poor transition to operations (BA). • Marketing values override other, perhaps more important, project issues (Boeing) – successful aeroplane but not project. • Severe operational pressures coupled with tight schedules realised from the outset and full systems view taken (GCHQ).
Designing complex systems • The System of Interest (project) exists within a Wider System of Interest (WSOI); ie the containing environment • The WSOI acts to constrain the System of Interest (SOI) • The SOI makes assumptions regarding the behaviour of the WSOI Wider System of Interest Constraints System Of Interest Assumptions ……importantly we can only contract to provide the system of interest! But we must understand the WSOI if we are to be successful.
Whole systems design handles complexity “The amount of information necessary to describe the behaviour of such a system is a measure of its complexity”. Requires a full system understanding to achieve this! “It is the hierarchical interrelationships that gives rise to the complex emergent behaviour”. Requires a full understanding of the interfaces involved to achieve this!