Date of Award

Spring 2012

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Mechanical Engineering

Committee Director

Han P. Bao

Committee Member

Miltiadis Kotinis

Committee Member

Alok K. Verma

Committee Member

Resit Unal

Abstract

In the present research the problem of enterprise-wide cost modeling is approached from a systems engineering standpoint. What this does is to use each stage of product life cycle to obtain useful information that helps in estimating the cost of the system. Once a generic framework is developed for estimating the core cost, layers of other factors that affect the cost are applied to the core cost, such as risk and uncertainty, maintainability, supply-chain and socioeconomic conditions. The cost model is expanded to accommodate a product domain ranging from a simple object to a system in the following hierarchy: System, Product, Assembly, Object. The cost model caters to the needs of cost estimation at every stage of the life cycle and for every kind of product, big or small, simple or complex. New process selection tools have been added to the field of cost estimation, which suggests the user with applicable processes given the material and production quantity. Attributes such as materials, fabrication processes etc… are ontology based. This enables a generic category to branch into increasingly specialized categories with each step. This is very useful, since in the preliminary stages of cost estimation, not much information is available as to what exact material or process is used. In such a case data pertaining to a more generalized material or process can be used.

Earlier work in the field of cost estimation has focused on specific areas of cost estimation either in terms of concept or application. In the work so far, no single-framework has been proposed that deals with cost estimation that fits the requirements at all stages of product development. Most importantly the concept of systems engineering has not been fully exploited in the area of cost estimation. The framework that we have proposed is based on systems engineering and hence can be used at any stage of the product development.

Some of the previous work on cost estimation has applications in specific industries. The framework guides the user in process selection at the lower levels based on material and quantity using a tool called PRIMA. If data is not available for a particular process, then a more generic form of the process can be chosen to collect cost data and estimate on the basis of that data. A more generic process is obtained by using the DCLASS tool. The cost can be revised to reflect more accurate process when the data and information is available. This is possible within the proposed framework.

The economic, environmental and social impact of the product has also been taken into account through EIOLCA models to make the framework enterprise-wide in nature. The framework has the potential to be developed into umbrella-software that has capability of estimating cost of small parts as well as large systems. The software will also have the capability to determine the economic, environmental and social impact of the products. The decisions regarding the product, the materials used, the manufacturing processes and even the mechanics of the system, are all determined and weighed against the economic, environmental and social impact. Based on this analysis, the policy makers can make micro as well as macro decisions during the initial planning phase of the system. Since the framework relies on principles of systems engineering, it can be applied to systems irrespective of industry and application.

As part of future work, suggestions have been made to turn the framework into a software suite along with other capabilities such as risk analysis and uncertainty.

DOI

10.25777/4em7-gr51

ISBN

9781267325013

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