Texas Equipment Replacement Model (TERM) Software Manual

The Texas Department of Transportation (TxDOT) owns and maintains an active fleet inventory of approximately 17,000 units, replacing about ten percent of them annually. Private and public agencies do not routinely use life-cycle cost as a replacement criteria because, until now, the only way to automate the inspection of thousands of life-cycle cost histories was to define an acceptability threshold for annualized costs. Most fleet managers rightfully consider this practice too inaccurate. The most relevant information provided by a life-cycle cost graph is its trend; units whose life cycle costs have been increasing longer and/or at a faster rate should have higher replacement priority. A major contribution of this research project is the development of the life cycle cost trendscore, a method that enables a computer to mimic replacement decisions made by a person visually inspecting a series of life cycle cost histories. Research project 7-4941 developed and tested the Texas Equipment Replacement Model (TERM), a computerized system that uses the trendscore to support equipment replacement decisions with life cycle cost based replacement criteria. TERM is a menu-driven system that can generate data tables and graphs, calculate and compare life cycle cost profiles and trends, and prioritize units for replacement based on fleet-wide comparisons of each unit's condition to the condition of all other units within its class. This report, the third of the 7-4941 series, consists of the TERM software manual.