All mentioned products of this scenario, the dam, the water supply system, the single-family house, the car park and the tunnel are part of an integrated maintenance planning strategy. This means that interventions within these systems must be coordinated to satisfy multiple maintenance objectives. Furthermore, maintenance tasks must be combined and bundled to minimize the total time of interruptions. Finally, a life cycle analysis is conducted to evaluate energy and water consumption, outputs of CO2, NoX and SO2 emissions and generation of costs of different design options.
Each system has three main interventions. The interventions are based on different intervals which are affecting the investigated values such as costs, duration time, energy consumption and environmental impacts. The values of the different maintenance costs are set for the shortest interval. The costs are rising from year to year by 10 % because of a failure increase in the less well maintained systems.
To combine all five subsystems we established a main system consisting dam, tunnel and drinking water supply. The main system is effecting the two subsystems house and parking house/garage. All five systems are connected by a road. The idea was to combine construction works of the main system because of the high dependency of the systems. So if you for example would have to close the dam due to maintenance (slip line etc.) it would directly affect the usage of the street and the tunnel due to reduced traffic. Because of the reduced traffic it is rational to also do maintenance work at the drinking water supply system at the same time, because the road has to be closed. At the same time it would not be sensible to maintain the house due to high noise pollution by machines, rather to maintain the garage (lower usage and fire protection).
First of all we investigated the total maintenance costs and the total duration time to figure out 7 representative combinations. Based on those representative combinations we analyzed the maintenance plan as well as the energy consumption and the environmental impact.
The design parameters including some boundary dimensions and durations can be found in the following table:
