A method to determine minimum contract bids for incentive highway projects
Abstract An increasing number of state highway agencies (SHAs) are using Incentive/Disincentive (I/D) bidding for highway construction. The I/D bidding concept is designed to shorten the total contract time by allowing the contractor to obtain incentives for early completion and pay disincentives for late completion of a project. Contractors are then presented with the problem of determining a better strategy to develop their bid estimate, including construction cost, construction time, and I/D. This research offers a quantifying model to determine an optimum low bid to submit for both linear I/D and escalating I/D type projects. A functional relationship between the construction cost and time duration is developed from the Florida Department of Transportation (FDOT) projects. The equation is then combined with the I/D to determine the optimum low bid price and time. Finally, several projects completed by the FDOT will be utilized to illustrate the validity of this model.
OPTIMAL BID MODEL FOR PRICE-TIME BIPARAMETER CONSTRUCTION CONTRACTS
Construction clients are increasingly calling for bids that require competing contractors to submit both the bid price and contract time. In such situations contractors are faced with the problem of deciding which combination of bid price and contract time to submit. An important consideration is the cost of time to the client. This varies from contract to contract and is usually expressed in terms of a unit time value such as liquidated damages rate or, for highway contracts, a daily road user cost. The unit time value is normally set out in the contract appendix and often used by the client as a basis for determining the contractor's total combined bid. This kind of procurement method is commonly referred to as the A + B method. To illustrate the mechanism of price-time biparameter procurement, a total combined bid Iso-map is developed in this study. The contractor's price-time performance curve is then incorporated into the map to determine the contractor's optimal bid parameters: tender price and contract time. Also, based on this mechanism, a mathematical optimization bid model is developed for calculating the optimal bid parameters.
Ground Fault Protection for Electric Utility Generating Station Medium Voltage Auxiliary Power Systems
Most generating station designs have medium voltage auxiliary power systems with low resistance grounded neutrals.1 In order to provide even higher reliability, the auxiliary power distribution system configurations supply increasingly redundant process equipment.