Ahmad Hadavi

Effects of high prequalification requirements

When designing a set of prequalification requirements, the first objective is to select the basic factors that are deemed appropriate to scrutinize, and the second objective is to establish the threshold for each of these factors to evaluate the capability and capacity of the bidders on a given project; together, these factors and the limits imposed on each constitute the basis for qualifying or disqualifying each of the bidders. To obtain the desired prequalification results and the consequent quality delivery of a project, both selecting the factors and determining the limits for each factor are crucial and must be given careful attention with due consideration of the prevailing environment (including market conditions, deadlines, need for technology transfer, etc.). In this study it was found that an improper design of prequalification requirements seriously affected the progress and cost of projects, provided opportunities for collusion, and encouraged the obtaining of contracts through improper practices. Based on an analysis of data from 30 Taipei Mass Rapid Transit projects, together with information gleaned from numerous interviews with contractors, consultants, and clients, it is shown that a risk-taking attitude by the Government and the establishment of relatively low prequalification requirements would be more conducive to achieving a desirable balance among (a) satisfying the schedule and sequence of contracting, (b) obtaining lower prices by an increase in competition, (c) procuring the timely delivery of a quality project, and (d) fostering the growth of local contractors.

Incorporation of nondestructive evaluation in Pontis Bridge Management System

The highway system in the United States includes nearly 577,000 bridges, the majority of which were built during two major bridge building periods -- just before World War II (1930s) and in the first two decades of the Cold War (1950s and 1960s). Given the age and increased usage of these bridges over the years, many now require substantial maintenance to satisfy their desired level of service. The complex task of allocating scarce funds for the repair, maintenance, and rehabilitation of this large number of bridges led to the development of several optimization studies and two major bridge management system, namely BRIDGIT and Pontis. Pontis has emerged as the system of choice for all states in the Nation. At this time over 40 highway agencies continue to license, evaluate and implement the current AASHTOWARE Program, Pontis V. 3.2. However, all data currently required by Pontis to assess the structural stability and resulting suggestions for repair and maintenance of bridges are based on visual inspection and judgement. Consequently, all suggestions are based on that visual inspection. This paper discusses development of a plan for how non-destructive evaluation (NDE) data can be used to provide more information than visual inspection.

Life-cycle cost analysis of bridges and tunnels

(Part 1) The whole life cost of a bridge consists of the total investment throughout the life of the bridge. This investment includes the initial construction cost, repair and rehabilitation costs, and all maintenance costs. An ability to determine the whole life cost of a bridge will help agencies evaluate the asset value of existing bridges, make better decisions on the design and construction of new bridges, and choose methods and approaches for rehabilitating existing structures such that the lowest life cycle cost is achieved rather than the lowest initial cost. Toward this end the whole life costs of Chicago trunnion bascule bridges are analyzed and found to be less than five times the initial costs for life spans exceeding 100 years. It was also shown that timely maintenance, repair, and rehabilitation can lower the life cycle cost of a bridge. (Part 2) This paper presents an analysis of life cycle costs for four bridges and two tunnels constructed and operated by the Port Authority of New York and New Jersey. Cost components include the initial cost, repair and rehabilitation costs, and annual maintenance costs. Results show that the maintenance and rehabilitation costs, as a percentage of the initial cost, are reasonably similar for both bridges and tunnels for perhaps the first 65 years of their service life, after which these costs increase significantly for bridges. However, based on cost per square foot and cost per traffic lane, the opposite is clearly true. Only time and detailed cost records for ensuing years will reveal how the two types of structure compare over their entire service lives.

Toward a Supply Chain Collaboration in the E-Business Era for the Construction Industry

Traditional business partnerships are changing in response to technology advancements and business innovations. Many companies have already reengineered their internal processes, and now the focus has shifted to their trading partners. With network connectivity, supply chain integration is the core strategic competence that enables many companies to act as one. A supply chain represents the cross-functional integration of activities that cross the borders of individual companies. This feature is very important in the constructions industry, because many firms must collaborate intensively throughout a project life cycle. The issues involved in selecting e-supply chain partners extend beyond choosing a trading partner or a contractor and must include configuring the business-tobusiness collaboration among the partners. In the future, supply chains, rather than enterprises (architect, engineer, construction contractor, manufacturer, and supplier), will compete with each other. There will be no isolated islands of automation, and the future of business applications will support collaborative commerce (C-Commerce). The ccommerce supply chain scheme enables a dynamic “virtual construction team” to fulfill many mission-critical business processes throughout a project life cycle, and it will undoubtedly be the best business solution for the new millennium.

Construction Industry Business Processes Modeled with Object-Oriented Approach

For the construction industry, the demands for optimization and greater efficiency become particularly urgent when the flow of project information extends beyond the borders of organizations. Driven by the need to attain even greater corporate competitive advantages, many business philosophies advocate the use of “the power of information technology to radically redesign business processes.” However, the adoption of IT in organizations and the configuration of IT in direct support of their business is a very complex process. As one step toward a solution, this paper focuses on the development of an Object-Oriented model for construction practices. An Object-Oriented approach is used to map the corporate business process with IT in terms of a series of reusable business objects, which encapsulate complex business rules. The major advantages of this approach are (a) the tedious redesign efforts of information systems can be waived and (b) applications can run on different platforms through Internet/Intranet connectivity. In contrast to an isolated IT system, this approach allows the construction business process to permeate different organizations, and communication in this system becomes process-to-process oriented.