RULE OF THUMB ESTIMATES OPTIMUM TIME TO KEEP CONSTRUCTION EQUIPMENT.

Construction firm executives prefer cost-wise decisions concerning whether and when equipment will be replaced. The problem is extensive since equipment spreads are both extensive and varied. Equipment needed to construct a pipe line deteriorates with use, and maintenance costs rise over time. These maintenance costs might include, among other things, (1) funds for a preventive maintenance program; (2) funds to be set aside for costs incurred due to equipment failures; (3) replacement parts, and (4) labor expenses for repairs. The problem of how to decide when to replace equipment is simplified with a 'life cycle analysis' which compares (over an infinite time horizon) any number of alternatives of maintaining or replacing machines and then identifies the optimum choice. A 'rule of thumb' approach to life cycle analysis for construction equipment can be performed by making some assumptions to simplify the usually complex calculations. A Hewlett Packard HP41-CV computation estimates the optimum retention period for construction equipment.