scholarly journals Evaluation of non-cost factors affecting the life cycle cost: an exploratory study

2016 ◽  
Vol 14 (4) ◽  
pp. 818-834 ◽  
Author(s):  
Ayedh Alqahtani ◽  
Andrew Whyte
Keyword(s):  
Life Cycle ◽  
Survey Data ◽  
Cost Estimation ◽  
Life Cycle Cost ◽  
Accurate Estimation ◽  
Capital Operation ◽  
Building Projects ◽  
Content Type ◽  
Factors Affecting ◽  
Cost Factors

Purpose This paper aims to identify the main non-cost factors affecting accurate estimation of life cycle cost (LCC) in building projects. Design/methodology/approach Ten factors affecting LCC in building project cost estimates are identified through literature and interviews. A questionnaire survey is conducted to rank these factors in order of priority and provide the views of cost practitioners about the significance of these factors in the accurate estimation of LCC. The data from 138 construction building projects completed in UK were collected and analysed via multiple regression to discover the relationship between capital and LCCs and between non-cost factors and cost estimation at each stage of the life cycle (capital, operation, maintenance and LCC). Findings The results of analysis of existing LCC data of completing project and survey data from cost professionals are mostly consistent with many literature views and provide a reasonable description of the non-cost factors affecting the accuracy of estimates. Originality/value The value of this study is in the method used, which involves analysis of existing life data and survey data from cost professionals. The results provide a plausible description of the non-cost factors affecting the accuracy of estimates.

APPLICATION OF COST SIGNIFICANT ITEMS TOWARDS IMPROVING ESTIMATION FOR LIFE CYCLE COSTING OF BUILDING PROJECTS

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Ayedh Alqahtani ◽  
Andrew Whyte
Keyword(s):  
Life Cycle ◽  
Life Cycle Cost ◽  
Construction Projects ◽  
Significant Cost ◽  
Building Projects ◽  
Factors Affecting ◽  
Complicated Process ◽  
Collection Data ◽  
Management Effort ◽  
Cost Factors

Construction projects have numerous variable factors affecting the value of life cycle-cost (LCC) and there is interaction between these factors, leading to complicated process. Therefore the current LCC models suffer from the absence of a standardized and a simple methodology of both the collection data and estimation LCC. Identification of the significant cost factors affecting the output of LCC is important step before embarking upon the collection of progress information. Furthermore, components of construction differ in their cost and time-importance, and thus management effort must be equivalently distributed. The concept of cost significant items (CSIs) is the best method to simplify estimation methodology as well as the collection data of construction projects. In general, The CSIs concept aims to determine the small number of items which represent a constant percentage of the LCC of construction projects. Therefore, this paper aims to present the explanation of each stage of LCC, the current classifications of asset components, the CSIs concept and previous practice of the significant cost items on the construction sector.

IDENTIFICATION OF THE KEY FACTORS FOR ACCURATE LIFE-CYCLE COST ESTIMATION FOR CONSTRUCTION

2014 ◽  
Vol 1 (1) ◽  
Author(s):  
Ayedh Alqahtani ◽  
Andrew Whyte
Keyword(s):  
Life Cycle ◽  
Cost Estimation ◽  
Life Cycle Cost ◽  
Prediction Models ◽  
Key Factors ◽  
Plant Resources ◽  
Factors Affecting ◽  
Low Visibility ◽  
The Cost ◽  
Cost Factors

A major limitation of Life-Cycle Cost (LCC) estimation/prediction modelling is the current typical reliance only on those factors that can be readily quantified and come easily to hand. While estimation of the cost of the most common labor, material and plant resources receive consideration because of their high visibility factor, there are several non-cost factors (low visibility factors) affecting the estimate that are often overlooked and, it is argued here, require equal consideration in estimation processes that seek optimum accuracy. Unfortunately, such (low-visibility) factors are neglected or ignored by current prediction models. Identification of these non-cost factors (low visibility factors) affects LCC estimate accuracy and can improve estimation process confidence. This paper critically reviews secondary research on identification of these important non-cost factors and subsequently determines their influence on the accuracy level(s) of construction cost estimation.

scholarly journals Estimation of life-cycle costs of buildings: regression vs artificial neural network

2016 ◽  
Vol 6 (1) ◽  
pp. 30-43 ◽  
Author(s):  
Ayedh Alqahtani ◽  
Andrew Whyte
Keyword(s):  
Life Cycle ◽  
Cost Estimation ◽  
Coefficient Of Determination ◽  
Percentage Error ◽  
Data Set ◽  
Building Projects ◽  
Content Type ◽  
Testing Stage ◽  
Running Cost ◽  
Artificial Neural

Purpose – The purpose of this paper is to compare the performance of regression and artificial-neural-networks (ANNs) methods to estimate the running cost of building projects towards improved accuracy. Design/methodology/approach – A data set of 20 building projects is used to test the performance of these two (ANNs/regression) models in estimating running cost. The concept of cost-significant-items is identified as important in assisting estimation. In addition, a stepwise technique is used to eliminate insignificant factors in regression modelling. A connection weight method is applied to determine the importance of cost factors in the performance of ANNs. Findings – The results illustrate that the value of the coefficient of determination=99.75 per cent for ANNs model(s), with a value of 98.1 per cent utilising multiple regression (MR) model(s); second, the mean percentage error (MPE) for ANNs at a testing stage is 0.179, which is less than that of the MPE gained through MR modelling of 1.28; and third, the average accuracy is 99 per cent for ANNs model(s) and 97 per cent for MR model(s). On the basis of these results, it is concluded that an ANNs model is superior to a MR model when predicting running cost of building projects. Research limitations/implications – A means for continuous improvement for the performance of the models accuracy has been established; this may be further enhanced by future extended sample. Originality/value – This work extends the knowledge base of life-cycle estimation where ANNs method has been found to reduce preparation time consumed and increasing accuracy improvement of the cost estimation.

Reliability Analysis of Repairable Systems Subject to System Modifications

1998 ◽  
Author(s):  
Z. H. Jiang ◽  
L. H. Shu ◽  
B. Benhabib
Keyword(s):  
Life Cycle ◽  
Steady State ◽  
Cost Estimation ◽  
Life Cycle Cost ◽  
Repairable Systems ◽  
Environmentally Conscious ◽  
Reliability Indices ◽  
Reliability Models ◽  
System Reconfiguration ◽  
Environmentally Conscious Design

Abstract This paper approaches environmentally conscious design by further developing a reliability model that facilitates design for reuse. Many reliability models are not suitable for describing systems that undergo repairs performed during remanufacture and maintenance because the models do not allow the possibility of system reconfiguration. In this paper, expressions of reliability indices of a model that allows system reconfiguration are developed to enable life-cycle cost estimation for repairable systems. These reliability indices of a population of repairable systems are proven theoretically to reach steady state. The expressions of these indices at steady state are obtained to gain insight into the model behavior, and to facilitate life-cycle cost estimation.

A Study of Life Cycle Costing in the Perspectives of Research and Commercial Applications in the 21st Century

2007 ◽  
Author(s):  
Wai M. Cheung ◽  
Linda B. Newnes ◽  
Antony R. Mileham ◽  
Robert Marsh ◽  
John D. Lanham
Keyword(s):  
Life Cycle ◽  
Cost Estimation ◽  
Life Cycle Cost ◽  
Academic Research ◽  
Life Cycle Costing ◽  
Electronic Products ◽  
Commercial Applications ◽  
The Uk ◽  
The Cost ◽  
Traditional Approaches

This paper presents a review of research in the area of life cycle costing and offers a critique of current commercial cost estimation systems. The focus of the review is on relevant academic research on life cycle cost from 2000 onwards. In addition to this a comparison of the current cost estimation systems is presented. Using the review findings and industrial investigations as a base, a set of mathematical representations for design and manufacturing costs and the introduction of the critical factors is proposed. These are considered in terms of the operational, maintenance and disposal costs to create a method for ascertaining the life cycle cost estimate for complex products. This is presented using as an exemplar, research currently being undertaken in the area of low volume and long life electronic products in the UK defence sector. The benefit of the method proposed is that it aims to avoid the inflexibility of traditional approaches which usually require historical and legacy data to support the cost estimation processes.

Integrating Reliability Analysis in Life Cycle Cost Estimation of Heat Exchanger and Pump

2014 ◽  
Vol 903 ◽  
pp. 408-413 ◽  
Author(s):  
FRESELAM Mulubrhan ◽  
Ainul Akmar Mokhtar ◽  
Masdi Muhammad
Keyword(s):  
Life Cycle ◽  
Heat Exchanger ◽  
Cost Estimation ◽  
Life Cycle Cost ◽  
Distribution Model ◽  
Maintenance Cost ◽  
Published Data ◽  
Acquisition Costs ◽  
Maintenance Policies ◽  
High Degree

This paper presents a mathematical model to estimate the life cycle cost (LCC) of heat exchanger and pump. Maintenance cost, down time cost and acquisition costs are calculated. The main uncertainty in calculating these costs are prediction of number of failure and cumulative down time. Number of failure is determined using failure and repair time density function. According to the characteristic that the cumulative failure probability observed, a Weibull distribution model is used. The scale and shape parameters of the Weibull are extracted from the published data. The results of the study show that 71.3% loss in the reliability of heat exchanger and 34.2% reliability loss in pump could lead to 66.2 % increment of the total cost. The reliability of the system decreases because of number of failures will increase each year, and this failure leads to unavailability of the system.Therefore in order to achieve higher system effectiveness and reduce the total LCC, the reliability of the systems need to be increased through proper maintenance policies and strategies. The results of the study could assist the managers to make decision with high degree of accuracy.

Sustainable construction

2020 ◽  
Vol 20 (2) ◽  
pp. 191-207 ◽  
Author(s):  
Muhammad Waseem Khan ◽  
Yousaf Ali
Keyword(s):  
Life Cycle ◽  
Rice Husk ◽  
Life Cycle Cost ◽  
Sustainable Construction ◽  
Partial Replacement ◽  
Content Type ◽  
Government Organizations ◽  
Construction Companies ◽  
Concrete Type ◽  
The Impact

Purpose The change in climate and depletion of natural resources because of the harmful emissions from different materials becomes a main issue for the globe. Some of the developed and developing countries have focused on this issue and performed research to provide a solution. The purpose of this study is to identify the best types of concrete based on its impact on the environment and economy. Design/methodology/approach The life cycle assessment and life cycle cost analysis of six concrete mixtures that include construction and demolition wastes (CDW), marble sludge, rice husk and bagasse ash as a partial replacement of cement, are performed. These types of concrete are compared with each other and with ordinary concrete to select the best possible concrete type for a developing country, like Pakistan. Findings The results show that, although for an agricultural country like Pakistan, the agriculture wastes such as rice husk and bagasse ash are preferable to be used, if the emissions of CO2 and CO from rice husk and NOx and SO2 from bagasse ash are properly controlled. However, based on the results, it is recommended to use the CDW in concrete because of the small amount of air emissions and affordable prices. Originality/value Through this study, a path has been provided to construction companies and relative government organizations of Pakistan, which leads to sustainable practices in the construction industry. Moreover, the base is provided for future researchers who want to work in this area, as for Pakistan, there is no database available that helps to identify the impact of different concrete on the environment.

scholarly journals Aviation Technology Life Cycle Management: Importance for Aviation Companies, Aerospace Industry Organizations and Relevant Stakeholders

2017 ◽  
Vol 5 (2) ◽  
pp. 15 ◽  
Author(s):  
Stanislav Szabo ◽  
Ivan Koblen
Keyword(s):  
Life Cycle ◽  
Cost Estimation ◽  
Life Cycle Cost ◽  
Aerospace Industry ◽  
Life Cycle Management ◽  
International Standards ◽  
Life Cycle Stages ◽  
Aviation Technology ◽  
Technology Life Cycle ◽  
System Life

<p align="LEFT">The paper in the introductory part underlines some aspects concerning the importance of Aviation Technology Life Cycle Management and informs on basic international standards for the processes and stages of life cycle. The second part is focused on definition and main objectives of system life cycle management. The authors subsequently inform on system life cycle stages (in general) and system life cycle processes according to ISO/IEC/IEEE 15288:2015 standard. Following the fact, that life cycle cost (LCC) is inseparable part and has direct connection to the life cycle management, the paper contains brief information regarding to LCC (cost categories, cost breakdown structure, cost estimation a.o.). Recently was issued the first part of Aviation Technology Life Cycle Management monograph (in Slovak: ”Manažment životného cyklu leteckej techniky I”), written by I.Koblen and S.Szabo. Following this fact and direct relation to the topic of article it is a part of article briefly introduced the content of two parts of this monograph (the 2nd part of monograph it has been prepared for the print). The last part of article is focused on issue concerning main assumptions and conditions for successful application of aviation technology life cycle management in aviation companies, aerospace industry organizations as well as from the relevant stakeholders side.</p>

Early Life Cycle Cost Estimation: Fiscal Stewardship with Engineered Resilient Systems

2017 ◽  
pp. 17-25
Author(s):  
Travis Moody ◽  
Robert Provine ◽  
Samantha Todd ◽  
Nicholas Tyler ◽  
Thomas R. Ryan ◽  
...  
Keyword(s):  
Life Cycle ◽  
Cost Estimation ◽  
Early Life ◽  
Life Cycle Cost
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