ABSTRACT
When an engineering structure is planned and designed, the decision analysis is generally performed to determine if the possible benefit induced by using the structure during its service life are larger than the investment cost. Once the engineering structure is built, structure managers will make effort to operate the structure safely, efficiently and cost-effectively. Over the last several decades, systematic approaches have been developed to establish well-conceived and balanced plans to maintain the structure efficiently and effectively under limited financial resources. The life-cycle cost analysis, which is known as the representative decision process for service life management of engineering structures, can provide the optimum times and types of inspection and maintenance, and structural performance during the expected service life. However, most existing studies for service life management are based on life-cycle cost analysis without considering the benefit from in-service structure. Therefore, more rational decision process is required integrating life-cycle cost and benefit over the service life.
This paper proposes the probabilistic approach to determine the optimum service life based on the cost-benefit analysis. This optimum service life is computed through the optimization formulation to maximize the effective cost-benefit which is defined herein as the difference between the cumulative benefit and life-cycle cost as shown in Figure 1. Depending on the profile of effective cost-benefit over time, the optimum service life becomes the value of infinite, finite or zero. The formulation of the cumulative benefit over time considers the availability and income from use of the engineering structure. Furthermore, in order to establish the cost-effective inspection and maintenance strategy as well as determine the optimum service life, the probabilistic approach proposed in this paper can be extensively applied. Effective cost-benefit over time: (a) Relation among the life-cycle cost, expected cumulative benefit and effective cost-benefit; (b) optimum service life associated with various effective cost-benefit profiles. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315207681/cd556cd4-4dcf-4efe-8e29-56fc67b8bfbd/content/fig338_1.tif"/>
