Defining Example: Long-term Maintenance of Complex Infrastructures
System: The system could be any major infrastructure (all are complex) or a set of interdependent infrastructures. Since the Minneapolis Bridge collapse is fresh in our minds, we can go with transportation as an example, although this would apply to any and all infrastructure systems.
Environment: The environment would be the collection of entities (people, governments, businesses) that create, maintain, use, and damage these infrastructures.
System of Systems: Large-scale infrastructures are, out of engineering necessity, composed of complex subsystems which themselves may be infrastructures. Transportation, for example, includes bridges, rail, roads, air, fuel, etc.
Complex: The problems of long-term maintenance involve interrelationships between elements. There are a number of such effects: repairs to one piece of infrastructure may only be effective or economical if a related piece is fixed; taking one piece of infrastructure off-line to do maintenance may move traffic to another area, causing the other piece to fail; money spent fixing one thing cannot be spent on another; new technologies may make certain infrastructures obsolete; catastrophic events can completely reshape the infrastructure and our ability to use it; social changes can reshape the environment in which the infrastructure exists. What is society’s maintenance responsibility on sunset infrastructure, and what complex effects can occur due to retiring an infrastructure?
Adaptive: The system’s behavior changes relative to its environment or as a result of internal interactions. Here the behavior we care about results from the cumulative effects of normal wear and damaging events, and how agents in the infrastructure adapt to those effects.
Aspirations: Aspirations include maintenance, replacement, and development of new technologies (not just old components) that allow us to improve the robustness and resilience of existing infrastructure. We desire to increase system awareness, anticipate long term problems, and proactively manage infrastructures, rather than react as they fail. Infrastructure should be cheap, robust, adaptable, repairable, easily replaced, disposable.
Approaches: Approaches include focusing engineering activities on wider concerns (more robust, less sensitive to technology change), behavioral change (be kinder to it so it lasts, construction near bodies of water is risky).
Attainability: Maintaining complex infrastructures is difficult because: The complexities make prioritization difficult; Public perception of risk makes funding difficult; and Effective decisions about maintaining large scale infrastructures, like transportation, should address longer time spans than we are used to thinking about. Engineering activities are increasingly focusing on the larger scope (e.g. “green companies” are focusing on wider issues of construction, use, disposal).