Introduction

Actually, the decision-making processes in the existing Bridge Management Systems (BMS’s) consider some form of Life-Cycle Cost Analysis (LCCA) of bridges; but none really use LCCA in making decisions regarding a specific bridge project. For example, Pontis® software utilizes a discount rate appointed by the bridge owner/manager to calculate action cost and benefits over time and in that sense utilizes life cycle principals. However, the LCCA and its application to bridges has received increased attention as a tool to assist transportation agencies in making investment decisions and in managing existing and future assets. This has resulted from the successful development of life cycle costing methodologies. However, this would largely depend on the availability and quality of relevant data.

The first component in an LCC equation is cost. There are two major cost categories by which projects are to be evaluated in an LCCA: initial expenses and future expenses. Initial expenses are all costs incurred prior to occupation of the facility. Future expenses are all costs incurred after occupation of the facility. Defining the exact costs of each expense category can be somewhat difficult at the time of the LCC study. However, through the use of reasonable, consistent, and well-documented assumptions, a credible LCCA can be prepared. One should also note that not all of the cost categories are relevant to all projects. The engineer is responsible for the inclusion of the pertinent cost categories that will produce a realistic LCC comparison of project alternatives. If costs in a particular cost category are equal in all project alternatives, they can be documented as such and removed from consideration in the LCC comparison. In other words, they can cancel each other out. An LCCA should be conducted as early in the project development cycle as possible. The primary purpose of an LCCA is to quantify the long-term economic implications. The initial structure decision with related various rehabilitation and maintenance strategies can be employed over the analysis period or service life (Figure 12.1)

The STADIUM® Life-Cycle Cost Software has incorporated an easy-to-use interface that enables designers to view the life-cycle costs for project alternatives from different perspectives, structure components, application of new operations, and cost timeline see figure 12.2.

Today, experts recognize that the key components of rational and functional bridge or asset management systems must include one or more databases that contain information on the characteristics of the assets being managed. In addition to data on the initial costs of the asset, the recommended databases may include;

Information on how structures and components deteriorate or result in reduced performance as a result of weather, traffic, and other “environmental exposure” factors;

Information and routines that quantify the effectiveness of various maintenance, repair, and rehabilitation strategies;

Information regarding the costs of various maintenance, repair, and rehabilitation strategies and replacement costs related to the functionality of the asset;

The present LCCA version considers the initial operations cost of construction and multiple future maintenance operations actions throughout the design life (figure 12.3)

Figure 12.1 – a. Timing of Maintenance and Rehabilitation Activities; b. Timing of Maintenance and Rehabilitation Activities in STADIUM ® LCCA for 3 alternatives

Figure 12.2 STADIUM® LCCA main window

Web site: http://www.simcotechnologies.com/