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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A knowledge based computer system for engineering design quotations

Mills, Paul January 1989 (has links)
The research examines the difficulties relating to the construction of a computer model for the automation of the design and cost estimation practices in engineering. The research has been carried out in an industrial context and the work has included both theoretical and pragmatic issues relating to the modelling of expertise for the production of commercially useful software in the field of combustion system design. The difficulties relating to the capture of ill-defined knowledge and subjective human decision-making with 'traditional' programming languages is examined and a study undertaken regarding the use of Artificial Intelligence techniques. A particular emphasis has been placed on decision-making under uncertainty. The work has resulted in the construction of a prototype expert system that can be used to produce design quotations relating to single burner gas-fired combustion systems. An important aspect of the decision-making characteristic of engineering design, and particularly for the cost estimating stages of a project, is the mannner in which engineers combine both cost and technical data in order to arrive at design solutions on the criterion 'value for money'. The formal mathematics of probability theory and confirmation theory provide tools for modelling expertise of this kind and the research has developed and examined two parallel systems. The first is based on the use of Bayes' theorem and the second makes use of ideas from both confirmation and fuzzy set theory. The general approach, developed within the research, of combining knowledge types relating to 'fitness for purpose' and 'cost' into ordinal measures of 'value' is fundamental to many areas of decision-making and has many applications. The research also addresses the use of rule-based methods for application domains where the knowledge is continually changing and the expertise of users is variable.
2

Estimating the cost of engineering services using parametrics and the bathtub failure model

Huang, Xiaoxi January 2012 (has links)
In the engineering domain, customers traditionally purchase a product by paying a one-off price to the supplier. Currently, customers are increasingly demanding engineering services in different disciplines, such as in the aerospace, defence, manufacturing and construction sectors. This means that the customer may buy a product, which includes an integrated service or purchase the usage of a product/service (i.e. availability and capability) rather than the ownership of a product. To meet this demand for engineering services rather than stand-alone products, many companies have moved from providing a tangible product to offering such services. In both academia and industry, the majority of the activities have focused on estimating the cost for products with little in the area of estimating the cost of providing engineering services. There appears to be a clear knowledge gap in the field of costing models and rules for providing such services. It is this gap in knowledge, which is the focus of the research presented in this thesis. This research is focused on estimating the cost for engineering services using parametrics and the bathtub failure model. This is illustrated through the application to a Chinese manufacturing and service provider. Eight years of cost-related data such as historical bills, service charges, maintenance records, and costs for storage has been collected. Observations, questionnaires and structured meetings have been conducted within the company. A methodology and a cost model for estimating the cost for engineering services are provided. The major contribution of this research is the creation of an approach, which is to estimate the cost of engineering services using parametrics and the bathtub failure model.
3

The early cost estimation of injection moulded components

Hosseini-Nasab, Hasan January 2002 (has links)
No description available.
4

Development of a Hierarchical, Model-Based Design Decision-Support Tool for Assessing Uncertainty of Cost Estimates

Ormon, Stephen Wayne 11 May 2002 (has links)
In order to identify ways to improve cost estimation, especially early in design, cost estimation needs to be viewed and represented as a process. An important activity within the cost estimation process is assessing the cost risk of a system. A decision-support tool that assesses cost risk should represent the impact of subsystem or system-level uncertainty and provide mechanisms to help select among competing designs. In order to address these problems, a generic cost estimation process was developed. It is based on an extensive review of the cost estimation literature. Also, a hierarchicial product structure, model-based approach and tool to estimate system-level cost risk was developed. This tool provides a link between cost models and cost elements for each component, mechanisms for determining the impact of risk on the cost of the design, and outputs used for selecting among alternative competing designs.
5

Computerized Cost Estimation For Forging Industry

Tunc, Mehmet 01 January 2003 (has links) (PDF)
In today&amp / #8217 / s life, companies are faced with the problem of providing quality goods and services at competitive prices. Cost estimation is a very important process for a forging company, as each time a quote is sent to a customer, the company earns or loses money depending on the results of the particular estimate. However, determining pricing for customer quotes is a matter of time consuming, detailed number of tasks repeated each time. Cost estimation software might do those tedious calculations and assist the estimator step by step to reach to a cost estimate in relatively short time. In this study, an interactive cost estimation software named Forge Cost Estimator, which performs the early cost estimation for forgings, has been developed. The program is aimed to be used by the cost estimators in hot forging companies. The software has various databases, which include material, forging and machining equipment data. The cost items defined in the forging work breakdown structure can be estimated by using different modules of the software and summed up in an additive structure by using the bottom-up costestimation method. For calculating the forge volume quicker and easier, a new volume estimation system named Easy-Volume, which is based on the volume fragmentation method, is proposed. The software can also guide the user in selecting the convenient forging production line. The software is written in MS Visual Basic 6.0. The developed program has been tested in a forging company and satisfactory cost estimations for several forgings have been achieved.
6

Cost Estimation For Commercial Software Development Organizations

Tagra, Dinesh, Tagra, Dinesh 21 October 2011 (has links)
The estimation of the software cost remains one of the most challenging problems in software engineering; as a preliminary estimate of cost includes many elements of uncertainty. Reliable and early estimates are difficult to obtain because of the lack of the detailed information about the future system at an early stage. However, the early estimates are really important when bidding for a contract or determining whether a project is feasible in terms of cost-benefit analysis. Estimators often rely on their past experiences for the prediction of effort for software projects. The fundamental factors that are contributing towards inaccuracy of the cost estimation process are imprecise and drifting requirements, information not readily available on past projects, and the methods that were developed and trained on specific data. In this thesis, we have developed a software cost estimation tool that helps commercial software-development organizations to effectively and quantitatively measure and analyze the software metrics based upon the functional requirements, operational constraints and organization’s capability to handle a project. This cost estimation tool is a fusion implementation or an essence of certain software measurement and estimation techniques that help a software organization to evaluate and analyze fundamental software metrics such as complexity, time, effort, and cost all of which are essential to improving turnaround time and attaining organizational maturity. The new cost estimation method is proposed for the iterative software development projects. The use case technique is implemented per iteration for the specification of the software requirements. COCOMO II and Function Point were used to compute the effort required for successive iterations. We also computed the magnitude of relative error for successive iterations. We tested the proposed method on student projects in order to illustrate its usefulness.
7

Comparative Analysis of the Cost Models Used for Estimating Renovation Costs of Universities in Texas

Faquih, Yaquta Fakhruddin 2010 August 1900 (has links)
Facility managers use various cost models and techniques to estimate the cost of renovating a building and to secure the required funds needed for building renovation. A literature search indicates that these techniques offer both advantages and disadvantages that need to be studied and analyzed. Descriptive statistical methods and qualitative analysis are employed to identify and compare techniques used by facility managers to calculate the expected renovation costs of a building. The cost models presently used to predict the cost and accumulate the budget required for renovation of a building were determined through interviews with ten Texas-based university facilities managers. The data and information gathered were analyzed and compared. Analysis of results suggests that traditional methods like Floor Area Method (FAM) is the most accurate, less time consuming, easy to use as well as convenient for data collection. Case-Based Reasoning (CBR), though not as widely used as FAM, is known to facilities managers. This is due to the fact that, if a new type of project needs to be renovated, and the data for a similar project is not available with the facilities manager, a completely new database needs to be created. This issue can be resolved by creating a common forum where data for all types of project could be made available for the facilities managers. Methods such as regression analysis and neural networks are known to give more accurate results. However, of the ten interviewees, only one was aware of these new models but did not use them as they would be helpful for very large projects and they would need expertise. Thus such models should be simplified to not only give accurate results in less time but also be easy to use. These results may allow us to discuss changes needed within the various cost models.
8

none

Lin, Hsih-Shiu 17 November 2008 (has links)
The sources of construction business for local firms have been shifted gradually to oversea market over years due to domestic economic recession. Nevertheless, the revenue seems standstill against to the growing contract amounts since the cost has been encroached on the present cost estimation procedure which based on personal instincts, experiences and simple formula that out of ability to identify the future uncertainties and frame the flexible management in advance under drastic business environment. To enhance the managerial insight and flexibility of evaluation process for the future uncertainties, we proposed and constructed a real optional model of risk cost upon traditional cost evaluation process. As a result of experiment, the sources of uncertainties and the flexibilities for management could be observed and directed clearly to against the risk without subjective or instinctive recognization anymore. Seveal occasions of application of real option value have been suggested in this study several important key points should be emphasized before using it: neither profit/loss nor price for accounting can be promised with the real option value; rather an expectable goal for managers to achieve. Appropriate flexible activities should be studied and approached before making decisions to acquire real option value. Maximized overall real option value could be a powerful competition tool for any company that tries to adopt real option approach to profit estimation if the interaction and synergy of real option among individual projects could be integrated effectively. Under the support of authority and interorganization commitment, the real option process should be learned and modified evolutionary according to dynamic business environment then becomes a strategic advantage.
9

Identifying the Economic Barriers to CLT Cost Estimation Among Building Construction Professionals

Stutesman, Jonathan Harley 04 February 2020 (has links)
Cross-laminated timbers (CLTs) are strong and lightweight structural building materials. CLTs are made from renewable wood resources and have significant economic potential as a new value-added product for the United States. However, market penetration has been obstructed by product affordability and lack of availability for use. Previous studies and projects have surveyed opinions of designers and contractors about the adoption of CLTs. No previous study was found that surveyed cost estimators, who serve the essential function of creating economic comparisons of alternative materials in commercial construction. CLTs are not included in these current cost estimation tools and software packages which may be limiting the potential use of CLT in construction. The purpose of this study was to discover if cost estimation is being used to make structural decisions potentially affecting the marketability of CLT use in construction and building design because of the ability to estimate CLTs adequately. Through the use of a survey, the re-designing of a building, and discussions with subject matter experts, this study examined the knowledge level of cross-laminated timbers of under-surveyed building construction professions and the relationship between cost estimation and structural material choices. Their responses are demonstrating the need for better cost estimation tools for cross-laminated timbers such as inclusion in the Construction Specifications Institute's classification systems in order for CLTs to become a more competitive product. The study concluded that cost estimation is important for CLT market development, because it is being used extensively in the construction industry. / Master of Science / Cross-laminated timbers (CLTs) are strong and lightweight structural building materials that also serve as a method of sequestering carbon rather than emitting carbon like more traditional construction materials. CLT construction is straightforward and quick to assemble, requiring minimal time and labor. CLTs are made from abundant and renewable wood resources and have significant economic potential as a job creator and as a new value-added product for the United States. However, market penetration has been obstructed by product affordability and lack of availability for use. Previous studies and projects have surveyed opinions of designers and contractors about CLT use. However, no previous study has been found that examined the opinions of cost estimators, who serve an essential function in providing economic comparisons of different construction systems for designers and building owners to select in the commercial construction area. CLTs are currently not included in these cost estimates, and this lack of information may be limiting the potential of this construction system. The purpose of this study was to discover if cost estimation is being used to make structural decisions potentially affecting the marketability of CLT use in construction and building design because of the ability to estimate CLTs adequately. Through the use of a survey and discussions with subject matter experts, this study examined the knowledge level of crosslaminated timbers of under-surveyed building construction professions and the relationship between cost estimation and structural material choices. They are demonstrating the need for better cost estimation tools for cross-laminated timbers such as inclusion in the Construction Specifications Institute’s classification systems in order for CLTs to become a more competitive product. Cost estimation is performed early in the design process before the structural material has been chosen. However, making cost estimates of CLT materials early in the design process is not a practical solution at this point due to the lack of cost data available. As an alternative solution, this project developed a design tool that is meant to accelerate the design process and allow companies to approach suppliers for quotes, which require mostly complete designs. While this is not a complete solution, if designs are made faster and more effortless, they should also be a more affordable investment for clients. 5 | Page Building construction professionals perceived CLT construction as too expensive, unavailable to the consumer, or unwanted by the client. It was found that the lack of data, due primarily to the material being new to the US construction industry, was a significant barrier to CLT cost estimation. The custom design of many previous CLT projects, due to the lack of CLT construction in the current building codes, limits the collection of standard CLT construction data. There is also an issue with the discrete sizes of CLT panels limiting their competitiveness. These barriers were identified in this study, and further research is needed to develop complete solutions.
10

A Break-Down Model for Cost Estimation of Composites

Joshi, Aniruddha V. 01 October 2018 (has links)
No description available.

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