The deteriorating state of the built environment has affected numerous sectors, and hospitals are no exception. Hospitals are relatively unique compared with other facilities because of the complexity of their systems and their criticality with respect to the communities they serve. Faced with limited budgets and pressures to comply with increasing performance requirements, hospital facility managers are required to strike a delicate balance between hospital maintenance costs and level of service requirements. Accordingly, this paper proposes a reliability-centered maintenance (RCM) approach that is combined with evolutionary optimization to develop optimal maintenance plans for hospital facilities. The scope of the developed model covers four mission-critical systems in hospitals, namely medical gases, primary HVAC, secondary HVAC, and elevators. Failure-mode effect analysis (FMEA) is used to determine the optimal maintenance strategy for various components within these systems. The model considers how each system contributes to the continuity of services in four areas within hospitals, namely intensive-care units, emergency rooms, operating rooms, and regular patient rooms. In order to demonstrate the capabilities of the developed model, a case study of a $\mathrm{5,200}\text{-}{\mathrm{m}}^2$ hospital is considered. Results demonstrate that by using the RCM and optimization approach, savings ranging from 6 to 16% in maintenance costs can be realized in comparison with traditional preventative maintenance approaches undertaken by existing maintenance contracts. The developed model is thus capable of providing hospital facility managers with an effective tool to better understand how their maintenance expenditures directly contribute to overall system availability and impact healthcare services delivered to patents.

Several researchers have attempted to formulate and solve different classes of the earthwork allocation problem. Linear programming (LP) and integer programming (IP) techniques have traditionally been applied to minimize transportation costs and mass-haul distances associated with earthwork processes. However, typical formulations of the earthwork allocation problem do not consider the sequence of equipment movement and are, therefore, limited in their ability to establish a practical and workable hauling plan. A more complex problem, which is formulated and solved in this research, is the least-cost route cut and fill problem (LCRCFP). The primary objective of the LCRCFP is to determine the specific route to be traveled and the quantities of soil that construction equipment must haul to meet the desired grade while minimizing the total distance traveled. In this research, the LCRCFP was formulated as a mixed binary optimization problem and solved using a traditional branch-and-bound method and a ...

The lack of effective and comprehensive risk identification leads to ineffective risk management, which accordingly leads to failure in achieving project goals. Previous research efforts related to simulating risks in construction projects mostly have been limited to viewing risks as segregated factors, and thus providing static analysis. This paper addressed this knowledge gap through a risk path simulation–driven approach that addresses construction risks as a continuum of risk sources, events, and project characteristics. The authors (1) identified 131 construction project risks by conducting an extensive literature review, (2) designed a risk path by analyzing risk paths available in the literature, capitalizing on identified benefits, and avoiding drawbacks, (3) conducted a project-based survey to collect data from 53 construction projects related to the magnitude and impact of occurrence of the identified risks on cost overruns, (4) developed a series of two genetic algorithm (GA) models and one artificial neural network (ANN) model to quantify the impact of construction risks on cost overruns, and (5) created an ontology model to facilitate data structuring and retrieval. An ontology is a data modeling tool used to represent unstructured information into structured forms. Results show that 80% of the risks identified in this research were found to have a significant impact on cost overruns, and 89% can be recognized at project initiation. The contribution of this framework lies in its ability to represent the cost impact of a chain of conditions and events, rather than a single-point risk factor using GA and ANN modeling techniques. The proposed framework may help industry practitioners assess the impact of significant construction risks on cost overruns.

Formwork systems have a considerable share in building construction costs. Accordingly, selecting an appropriate formwork system that respects project individualities plays an important yet challenging role in achieving significant cost savings. In Egypt, current practice in formwork selection primarily uses the subjective decisions of site engineers. This paper presents a fuzzy logic-based model that supports decision makers in selecting the appropriate vertical formwork system for projects. Ten commercial vertical formwork systems commonly used in Egypt are identified with the most important factors affecting their selection. The data were tabulated to serve as a knowledge-based system (KBS) to guide site engineers in selection. On the basis of the KBS, a fuzzy logic model with five input variables, representing the governing factors, is then developed to automate the selection process. The model is tested by applying it on a real-life case study. Results are acceptable and show a promising role...

Performance-based road maintenance contracts (PBRMCs) are an effective mechanism to transfer risk and responsibility of road maintenance activities to the private sector. Proper structuring of performance indicators and the extent of penalties and incentives in the contract has a significant effect on the overall cost and level of service (LOS) provided to the public. This research develops a series of mathematical optimization models and a computational tool that allows road agencies and contractors to better structure the following contractual conditions in a performance-based contract (PBC) for road maintenance: (1) types of performance indicators to be considered; (2) their threshold levels; and (3) the appropriate levels of penalties and incentives. The availability of such models and tools will allow road agencies and contractors that are unfamiliar with PBRMCs to make informed decisions on their approach to contractual risk allocation. A case study of a major highway in Egypt is presented to demonstrate how slight changes in performance thresholds and contractual penalties affect the overall lifecycle costs (LCC) and eventual road performance. The results demonstrate that: (1) small variations in KPI thresholds can have a significant effect on the overall lifecycle costs and eventual contract price; and (2) the addition of penalties and incentives can be an effective mechanism to ensure contractors adhere to performance requirements in PBRMCs.