Background/Objectives. Reserve cost estimates for complex contaminated sites are subject to numerous sources of uncertainty that BNSF’s prior estimating processes were not adequately addressing. The following five types of uncertainty were the most critical to life cycle costs: 1. The potential remedial options to remediate a site’s impacts 2. The associated costs for each option 3. Agency requirements/decisions 4. Time period of remedial actions and monitoring 5. Extent and type of contamination or other unknowns Methods consistent with ASTM 2137-01 were evaluated to better address these uncertainties and more accurately estimate life-cycle costs. The method chosen, Decision Tree Modeling, also allowed for more effective implementation of strategic and financial planning as well as a foundation to better incorporate value engineering into our site management processes.
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