Cost Estimating

This paper describes a project undertaken with industry to develop a software tool that automates the configuration of conceptual aircraft systems so that their costs can be estimated. The development of accurate cost estimates at the conceptual design stage helps identify ways to reduce costs throughout a project's life cycle. A case study on the Hydraulics system is used to demonstrate a novel methodology for capturing and representing the design rules. The developed prototype requires Top Level Definition (TLD's) of the proposed new aircraft design and then uses the captured design rules together with rationalised judgements to calculate the architecture and a pseudo Bill of Materials (BOM) for a conceptual system. Subsequently the generated system is costed using a commercial cost estimating software. The piping cost and its installation is calculated within the tool and added to the output from the commercial software. This tool allows different configurations to be com...

Complete List of Authors: Di Stefano, Paolo; Universita' degli Studi di L'Aquila, Department of Mechanical Engineering Di Angelo, Luca; Università degli Studi di L'Aquila, Department of Mechanical Engineering ... Keywords: RAPID PROTOTYPING, COST ESTIMATING, E-...

Estimation is the first step in the project development process. Information technology provides an efficient platform for estimators to obtain quotations and specifications for their bid estimates. However, in practice, project overhead estimation relies heavily on the professional judgement and intuition of the estimators. This reduces the overall accuracy and reliability of the bid and a better understanding of the

... survey was conducted to gain a better understanding of this multibillion dollar industry, which is relatively unfamiliar to many in the construction sector. ... performed (eg, applications, value, duration, type of product installed), and bidding and estimating practices (eg, productivity ...

Little research has been carried out on before-and-after studies of traffic and construction costs in large transportation infrastructure projects. The few studies that do exist show that forecasts of construction costs tend to be underestimated and those of traffic, overestimated. An examination of construction costs and traffic in seven large Danish bridge and tunnel projects indicates that, on average, construction costs were underestimated and traffic was overestimated in the initial phases of planning. This pattern is also found for similar ...

Little research has been carried out on before-and-after studies of traffic and construction costs in large transportation infrastructure projects. The few studies that do exist show that forecasts of construction costs tend to be underestimated and those of traffic, overestimated. An examination of construction costs and traffic in seven large Danish bridge and tunnel projects indicates that, on average, construction costs were underestimated and traffic was overestimated in the initial phases of planning. This pattern is also found for similar ...

This review evaluates a diverse portfolio of technologies that produce hydrogen from renewable energy sources. A number of literature surveys and efficient hydrogen formation pathways are compared. The continuous improvement in hydrogen production pathways is of crucial importance in the making of hydrogen from sustainable energy sources. Evaluation of the economics in producing hydrogen from natural gas (NG), coal, biomass, atoms, sunlight and wind shows that the key to commercialization of hydrogen energy depends on feedstock cost, raw material availability, capital costs of equipment and how long the technology has been established. Estimates reveal that the hydrogen production cost (HPC) from coal is expected to be 0.36 to 1.83 US/kg, whereas for NG it is 2.48 to 3.17 US/kg. Depending on the type and cost of raw material employed, the HPC from biomass is expected to be in range of 1.44 to 2.83 US/kg, while the HPC from wind is expected to be 5.50 US/kg depending on the size of wind turbines and type of electrolyzers used. Compared to the HPC from coal and NG, the HPC from solar energy is much more higher (by more than 3 orders of magnitude). Considering the capital cost, energy consumption and operating costs, a HPC of 8 US/kg would be expected for the electrolysis of water. Nevertheless, if the cost of electricity is low, then it would be possible to produce hydrogen from solar and water electrolysis at a cheaper rate. This result implies that hydrogen production from coal, biomass and NG resources will be great enough to meet hydrogen demands in the near future. Of all of the current technologies employed for the yield of hydrogen from fuels, steam methane reforming (SMR) seems to be the most practical and established technology. By the SMR pathway, HPC from NG is expected to be 3.50 US/kg and 1.25 US/kg for small and large plant sizes, respectively, while the HPC from NG is estimated to have a cost of 6 US/GJ. However, production technologies including thermochemical pathways such as biomass gasification, pyrolysis, and supercritical water gasification (SCWG) and biological pathways such as photosynthesis, fermentation, and biological water gas shift reactions (BWGS) are also discussed. © 2014 American Chemical Society.

http://pubs.acs.org/doi/pdfplus/10.1021/ef5007808