scholarly journals Probabilistic and Fuzzy Approaches for Estimating the Life Cycle Costs of Buildings under Conditions of Exposure to Risk

2019 ◽  
Vol 12 (1) ◽  
pp. 226 ◽  
Author(s):  
Edyta Plebankiewicz ◽  
Wiesław Meszek ◽  
Krzysztof Zima ◽  
Damian Wieczorek

The paper discusses issues related to life cycle costs in construction. Life cycle cost is a key element in the assessment of environmental sustainability in construction and it provides a tool for the economic evaluation of alternative sustainability options exhibiting different capital, operating costs or resource usage. The authors reviewed selected models of estimating life cycle costs in construction, drew attention to the complex mathematical models developed so far, namely those which take into account only financial risks and those which involve the possibility of the influence of other risk factors and described the main assumptions accompanying the original model for estimating the whole life costs of buildings, including: reasons for choosing theory of possibility, division and parametrization of input data. The aim of this paper is to confirm the validity of the model structure assumptions adopted by the authors by comparing the originally selected fuzzy approach to calculating life cycle costs taking into account the risk with the probabilistic approach, as well as indicating the domain in which the probabilistic approach will complement the fuzzy approach chosen by the authors. The paper presents a comparison analysis of two approaches used in the authors’ model, a fuzzy and a probabilistic approach, recommended by the ISO standard 15686-5:2008. The authors used the Oracle Crystall Ball software in their simulations.

Author(s):  
Igor S. Ondryas

In the increasingly competitive global marketplace the users of industrial products face the challenge of predicting accurate life-cycle costs of their equipment and machinery. The deregulation of many industries resulted in inability of operating companies to pass over to the customer the increased costs of their products, which may have been caused by inaccurate predictions of the equipment operating costs. This evolution in the 1980’s have emphasized the need for accurate predictions of the equipment operating costs and have meant the difference between profit and loss. This paper presents the concept of equipment Durability to be used in the process of evaluation the equipment life cycle cost and subsequent equipment selection. It is also the first part or primer to the paper which describes the Durability Surveillance Program on the Advanced Gas Turbines sponsored by EPRI titled “Durability Surveillance Program on the Advanced Gas Turbine GE Frame 7 F” (1).


2021 ◽  
Vol 13 (12) ◽  
pp. 6974
Author(s):  
Charlotte Cambier ◽  
Waldo Galle ◽  
Niels De De Temmerman

In addition to the environmental burden of its construction and demolition activities, the Flemish housing market faces a structural affordability challenge. As one possible answer, this research explores the potential of so-called expandable houses, being built increasingly often. Through specific design choices that enable the disassembly and future reuse of individual components and so align with the idea of a circular economy, expandable houses promise to provide ever-changing homes with a smaller impact on the environment and at a lower cost for clients. In this paper, an expandable house suitable for various housing needs is conceived through a scenario-based research-by-design approach and compared to a reference house for Flanders. Subsequently, for both houses the life cycle costs are calculated and compared. The results of this exploration support the proposition that designing expandable houses can be a catalyst for sustainable, circular housing development and that households could benefit from its social, economic and ecological qualities. It requires, however, a dynamic perspective on evaluating their life-cycle impact.


2021 ◽  
Author(s):  
Amir Fereidouni Kondri

This report presents the methodology for determining least cost energy efficient upgrade solutions in new residential housing using brute force sequential search (BFSS) method for integration into the reference house to reduce energy consumption while minimizing the net present value (NPV) of life cycle costs. The results showed that, based on the life cycle cost analysis of 30 years, the optimal upgrades resulted in the average of 19.25% (case 1), 31% (case 2a), and 21% (case 2b) reduction in annual energy consumption. Economic conditions affect the sequencing of the upgrades. In this respect the preferred upgrades to be performed in order are; domestic hot water heating, above grade wall insulation, cooling systems, ceiling insulation, floor insulation, heat recovery ventilator, basement slab insulation and below grade wall insulation. When the gas commodity pricing becomes high, the more energy efficient upgrades for domestic hot water (DHW) get selected at a cost premium.


2015 ◽  
Vol 31 (4) ◽  
pp. 1969-1990 ◽  
Author(s):  
T. Y. Yang ◽  
M. Murphy

Steel is one of the most popular seismic force–resisting systems (SFRS) in use worldwide. In Canada, several SFRS have been prequalified for use in the national and provincial building codes. The design of each SFRS has been covered comprehensively in literature. However, no guidance has been provided in selecting the optimum system for a project. In this paper, a prototype building located in Vancouver, Canada, was designed nine times to utilize each of the prequalified SFRS. Detailed seismic hazard and finite element models were developed for each system. The performance in terms of initial construction and life-cycle cost was used to rank each SFRS. The result of this analysis shows that the eccentrically braced configuration has the lowest material usage and life cycle maintenance cost; it is therefore the most economic system in this study. The presented methodology is transparent and can be easily adopted by engineers to select the most economic seismic system for projects with different configurations and geometries than those given in this research. Furthermore, this system introduces a metric with which to estimate the life-cycle costs of a structure taking into account seismic damage over the service life.


Author(s):  
A. J. Schuetz

A conceptual design study has been conducted for an all-new, land-based patrol aircraft for the U.S. Navy. The selected propulsion system was a conceptual high-speed turboprop. An antisubmarine warfare mission was chosen for the design flight profile. Probable peacetime utilization was postulated so that the engine duty cycle could be estimated. Aircraft designs were optimized for minimum takeoff gross weight (TOGW) and for minimum life cycle cost (LCC). It was shown that the aircraft performance requirements and design constraints bound the optimization process so tightly that the same point design is obtained for both TOGW and LCC criteria. The contribution of the engine costs to the overall life cycle costs was examined. The sensitivity of the aircraft optimization to the engine characteristics — specific fuel consumption (SFC), length, diameter, and cost — was analyzed. It was determined that SFC is the most significant engine characteristic.


Author(s):  
Laxman Y. Waghmode ◽  
Ravindra S. Birajdar ◽  
Shridhar G. Joshi

It is well known that the pumps are the largest consumers of industrial motor energy and account for more than 25% of electricity consumption. The life cycle cost of a pump is the total lifetime cost associated with procurement, installation, operation, maintenance and its disposal. For majority of heavy usage pumps, the lifetime energy and/or maintenance cost will dominate the life cycle costs. Hence a greater understanding of all the cost components making up the total life cycle costs should provide an opportunity to achieve a substantial savings in energy and maintenance costs. This will further enable optimizing pumping system efficiency and improving pump and system reliability. Therefore in this context, the life cycle cost analysis of heavy usage pumps is quite important. This paper focuses on an application of a methodology of determining the life cycle cost of a typical heavy usage multistage centrifugal pump. In this case, all the cost components associated with the pump-set have been determined and classified under different categories. The data with regard to initial investment costs, operation costs, maintenance and repair costs and disposal costs for the pump considered for this case study was collected from the concerned pump manufacturer along with the unit cost of each component, quantity used and their weights. By applying the principles of reliability and maintainability engineering and using the data obtained from the design, manufacturing and maintenance departments, the component-wise values of MTBF (Mean Time Between Failures) and MTTR (Mean Time To Repair) were estimated. The results of the life cycle cost analysis of the specimen pump were compared with the life cycle costs of similar pumps reported in the literature. From this comparison of results, it can be concluded that, the initial cost of the pump is the only a fraction of the total life cycle cost. The operating cost of the pump dominates the life cycle costs especially in case of heavy usage pumps. The maintenance cost varies approximately from 0.6 to 2.5 times the initial cost of the pump. The life cycle cost of the pump varies approximately from 12 to 33 times the initial cost of the pump. The operation and maintenance cost is almost 92 to 97 per cent of the life cycle cost. The detailed analysis carried out in this paper is expected to provide guidelines to the pump manufactures/practicing engineers in selecting a heavy usage multistage centrifugal pump based on the total lifetime cost rather than only on initial price.


1989 ◽  
Vol 111 (4) ◽  
pp. 637-641
Author(s):  
R. B. Spector

When aeroderivative gas turbines were first introduced into industrial service, the prime criterion for assessing the “relative value” of equipment was derived by dividing the initial (or capital) cost of the equipment by the number of kilowatts produced. The use of “dollars per kilowatt” as an assessment parameter emanated from the utility sector and is still valid providing that the turbomachinery units under consideration possess similar performance features with regard to thermal efficiency. Second-generation gas turbines being produced today possess thermal efficiencies approximately 45 percent greater than those previously available. Thus, a new criterion is required to provide the purchaser with a better “value” perspective to differentiate the various types of turbomachinery under consideration. This paper presents a technique for combining the initial cost of equipment with the costs of fuel consumed, applied labor, and parts to arrive at an assessment parameter capable of comparing the relative merits of varying types of turbomachinery. For simplicity, this paper limits the life cycle cost derivation and discussion to turbogenerator units; however, the principles of this type of life cycle analysis can also be applied to gas turbines in mechanical drive applications and/or combined cycles.


Author(s):  
E. J. Bentz ◽  
C. B. Bentz ◽  
T. D. O’Hora

Abstract This paper provides a comparative assessment of low-level radioactive waste (LLW) life-cycle costs for U.S. commercial disposal facilities. This assessment includes both currently operational facilities and planned commercial facilities. After identifying the individual facility’s operational period, current or planned capacity, and historical disposal volumes (where applicable), the paper describes the respective facilities’ waste acceptance criteria, anticipated waste characteristics, and disposal technologies employed. A brief identification of key components of cost categories that constitute life-cycle cost for the disposal facilities is provided, as well as an identification of factors that affect life-cycle cost. A more specific comparison of certain life-cycle cost components for the disposal facilities is provided, with regard to U.S. LLW disposal volumes and characteristics. Similarities and differences in total life-cycle cost and life-cycle category-specific costs among the U.S. facilities are presented and discussed. The data presented reveals that: • No new LLW commercial disposal facilities have been sited in the U.S. since 1988, and that siting of LLW disposal facilities in the U.S. has become increasingly difficult and contentious, necessitating long lead times and significant up-front costs — without any certainty of success. • Overall, life-cycle costs for LLW disposal at U.S. commercial facilities have increased significantly over time, reflecting increased regulatory compliance requirements, state-imposed access fees and taxes, local community hosting incentive costs, and cost escalation inherent in delays in establishing facilities or modifying existing licensed facilities. • Life-cycle costs are also significantly affected by the nature of the engineered isolation technology employed, reflecting the geologic characteristics of the siting location and the activity levels of the wastes accepted. • Since many of the newly-planned facilities anticipate receiving lower total volumes with an increasingly greater percentage of higher activity wastes (than historical volumes disposed) and are to be sited in more ecologically sensitive geologic regions, they will require more comprehensive — and hence more expensive — engineered isolation technologies. As a result, currently planned facilities are anticipated to experience significantly higher total life-cycle costs than existing operational facilities.


2019 ◽  
Vol 9 (1) ◽  
pp. 129-133
Author(s):  
M. Rogalska ◽  
D. Szewczak

AbstractIn the article the costs of alternative roofing techniques in the life cycle of the building were calculated. The calculations were made in accordance with ISO 15686-5 standard “Buildings and constructed assets – Service life planning – Part 5: Life-cycle costing”, using normative durability periods and minimum period of annual consumption of individual building elements to determine the durability of building components. The normative periods are valid in Poland in relation to the valuation of buildings. Probabilistic costs in the life cycle of ceramic, metal and bituminous coatings were analysed. The probability density distributions were assumed: beta for pricing factors and normal for the interest rate. Calculations were carried out for the periods of 100 years of operation of coverings, taking into account the costs of replacement and utilization. As a result of the calculations, the life cycle costs of alternative coatings with probabilities from 5 to 95% were obtained.


Author(s):  
Prabir Panda ◽  
G. P. Sahu

Studies highlight that public procurement in any country acts as a barometer of public confidence in fairness and transparency of public institutions. A number of cases related to corruption in public procurement in the country have been highlighted by media on regular basis. These incidents raise questions regarding robustness of the procurement framework in vogue in the country. Though no special legislative framework dealing with public procurement exists in the country, the administrative guidelines on the subject are quite exhaustive. Procurement is not a state subject; hence law can be made by the Centre for entire country. However, no separate law governing public procurement has been enacted in India. However, public procurement in India is not bereft of its share of issues. Multiplicity of instructions, absence of procurement law and singular emphasis on upfront value of acquisition without considering life cycle cost mars public procurement in India. Further, social and environmental sustainability has also not received the attention it deserves. Studies highlight that migration of public procurement to Internet could provide us savings of up to 25% by streamlining 30% of Indian Union Budget spent on provisioning of goods / services. However, any such endeavor has 70% chances of failure. With only 13% e-procurement research focusing on public sector make matter worse. In the above backdrop, the chapter would cover: Importance of public procurement, Difference between public and corporate procurement, Overview of procurement framework of the country - covering constitutional/ legislative/ administrative provisions, generic public procurement process, various types of procurements – limited tender, open tender, single tender, issues in public procurement of the country and e-procurement initiatives by Government of India and status thereof.


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