In the Life-Cycle-Assessment of integrated civil engineered systems, deterioration and failure rates play a crucial part. Deterioration describes the process, a product loses functionality and in the end has to be maintained to keep this function. Those interventions of course have to meet some cost benefit factor.
The here presented environmental system consists of the following subsystems: Wind Power Plant, Reverse Osmosis Plant, Dam and Tunnel.
Due to existing dependencies of those systems, maintenance have to be coordinated and bundled to minimize costs and down time. To develop maintenance strategies for those integrated systems, it is important to understand their relations, interfaces and interdependence’s. All systems deteriorate differently and have different specified maintenance intervals and strategies, as it is presented in the individual systems pages.
Figure 1: Explanation Interfaces
For each system only one system configuration is considered. Each has three different interventions that distinguish in down time and costs. The presented system of systems is located around a river delta around the coastline. This river is hold back by a dam, and crossed by a tunnel. both providing infrastructure to cross the river. At the coast a reverse osmosis plant and a offshore wind park are located. The offshore wind turbine and dam are providing energy for the reverse osmosis plant and the tunnel to work, while the reverse osmosis plant uses the tunnel as infrastructure to transport the fresh water on the other side of the river. When this passageway is down for some reason (e.g maintenance), the fresh water is stored within the dams reservoir.
The figure below displays the interdependence’s of those systems regarding eventual down time caused by maintenance. To have the whole system of systems running properly, only one sub-systems in the dashed lines is allowed to be maintained at once. The following life-cycle assessment takes a closer look at different combinations of maintenance of those four systems and maintenance plans as well as the environmental footprint is considered.
Figure 2: Explanation Maintenance Interdependence’s