Life Cycle Cost Estimation Research Articles

Product-service system engineering characteristics design for life cycle cost based on constraint satisfaction problem and Bayesian network

A product-service system (PSS) has many engineering characteristics (ECs), their design is a critical work in PSS planning, which has an important influence on the cost and quality of PSS. How to design a reasonable PSS-ECs scheme, and evaluate its life cycle cost (LCC) is a challenging task. Aiming at the PSS-ECs design for LCC, this paper proposes a new PSS design method, it first treats and models the design of PSS-ECs as a customer requirements-based constraint satisfaction problem (CSP) for finding an initial set of satisfied PSS-ECs schemes, and then it evaluates these schemes based on Bayesian network (BN)-based LCC estimation model for finding an optimal scheme as a solution. Constructing a BN describing the uncertain relationships between PSS-ECs and LCC is the core of this research. By combining existing R&D data and expert experience, Bayesian estimation and arithmetic averaging are used to estimate the conditional probability in BN. Take a subway bogie and its maintenance service in a Chinese company as an example to verify the proposed method. The results show that the proposed method can effectively solve the problem of PSS-ECs design for LCC, it also shows that this method has positive significance in realizing engineering knowledge consolidation, assisting designers in exploring design space, and improving the rationality of design decisions.

Разработка календарно-плановых производственных показателей на основе модели жизненного цикла оборудования

The article is devoted to the problem of substantiation and regulation of calendar and planned production indicators. Estimation of the equipment life cycle cost at the stage of investment in its acquisition and commissioning will make it possible to make decisions on the usefulness period, on the indicators of production capacity and the level achieved, on the permissible values of equipment downtime, the expediency of working on its maintenance and other indicators related to the use of production equipment.

Инвестиционный проект создания замкнутых водооборотных циклов на промышленном предприятии

Due to the considerable costs involved in industrial wastewater treatment, the introduction of open (low-discharge) and closed water circulation systems is the most sensible way to prevent environmen-tal pollution at industrial companies. Since the level of circulating water treatment can be much lower than that required for discharge into a water body, the installation of closed water circulation systems can achieve both the economic and total effects of environmental protection. Despite the seemingly obvious advantages of this approach, it requires a serious feasibility analysis. The life cycle costs of a construction project can be estimated according to GOST R 58785-2019 Water Quality. Life Cycle Cost Estimation for Efficient Operation of Water Supply and Sanitation Systems and Facilities. However, at the initial (pre-project) stage, the analysis can be based on benchmarks. Large industrial companies make extensive use of foreign estimation methods. The paper presents the results of a feasibility analysis obtained using different methods to justify investments in the reconstruction of wa-ter treatment facilities at an oil refinery.

Fatigue reliability assessment and life-cycle cost analysis of roadway bridges equipped with weigh-in-motion systems

The fatigue safety assessment of critical details in steel bridges is dominated by several uncertainties mainly related to load modelling. The use of integrated weigh-in-motion (WIM) systems in roadway bridges allows to collect all the necessary information for tracking actual traffic conditions. Based on WIM data, the uncertainty associated to the evaluation of the probability of fatigue failure is reduced, allowing the optimal scheduling of repair and maintenance activities and thus improving safety and economic savings. The paper presents a methodology for estimating fatigue life cycle cost (LCC) of roadway bridges equipped with a WIM system that considers uncertainties in measurement and modelling errors. The procedure allows the quantification of the economic gain enabled by WIM systems, useful in assessing the cost/accuracy trade-off for a given WIM system. It is found that the continuous use of a WIM system may improve the rate of decrease of the structural reliability index, compared with temporally limited use of WIM data. The periodic update of the reliability index and of the probability of failure based on WIM measurements results in a rather accurate estimation of the fatigue life cycle cost, which is crucial in identifying the payback time of the WIM system.

Holistic Impact and Environmental Efficiency of Retrofitting Interventions on Buildings in the Mediterranean Area: A Directional Distance Function Approach

The study focuses on the application of a nonparametric methodology for evaluating the sustainability of retrofitting interventions to be applied on different typologies of buildings and different climate zones of the Mediterranean area. The paper starts from the analysis of data collected through the HAPPEN project, that is a H2020 European project which proposes a holistic approach for a deep and sustainable renovation of the Mediterranean residential Building stock. Even if the European Commission allocated considerable funds for retrofitting interventions, the choice of the optimal solution is not always that easy because several variables have to be considered. The present manuscript proposes a methodology to compare different retrofitting solutions combining Life-Cycle Cost (i.e., LCC) estimations with the nonparametric Directional Distance Function approach (i.e., DDF). In detail, the literature suggests that the DDF can be effectively used for comparing different observations through efficiency scores. The main result of the paper is the definition of a hybrid methodology that, starting from estimates of LCC and applying a DDF technique, represents a simple method for evaluating the best retrofitting intervention. Results are represented by two scores where the former represents a holistic efficiency measure, while the latter shows an environmental efficiency score.

Performance-based seismic retrofit of RC structures using concentric braced frames equipped with friction dampers and disc springs

In this study, concentric braced frame installed with a friction damper-disc-springs is proposed to enhance the seismic performance of RC framed structures. The structural configuration of the retrofit is outlined and the analytical model is explained. A performance-based seismic retrofit procedure combined with a genetic algorithm (GA) optimization is proposed to obtain the optimum design variables of the retrofit. 2D and 3D structural models are used as case studies. The effectiveness of the proposed retrofit is assessed through non-linear time-history response analysis (NLTHA), fragility analysis, and seismic life cycle cost (LCC) estimation. To ensure that concrete stresses after retrofit are within acceptable limits, finite element method is used. The results show that the proposed retrofit technique is effective in reducing the maximum inter-story drift ratio and in eliminating the residual drift of the model structures significantly. In addition, the probabilities of exceeding different limit states and the total seismic LCC are significantly reduced compared to the un-retrofitted cases.

Life cycle cost estimation and environmental valuation of coal mine tailings management

Sustainable mining management is increasingly seen as an important issue in achieving a social license to operate for mining companies. This study describes the life cycle cost (LCC) analysis and environmental valuation for several coal mine tailings management scenarios. The economic feasibility of six different options was assessed using the Net Present Value (NPV) and Benefit-Cost Analysis (BCA) methods. These options were belt press (OPT 1), tailings paste (OPT 2), thickened tailings (OPT 3), and OPT 1 with technology improvement and renewable energy sources (OPT 1A-C). The results revealed that OPT 1A (belt press technology with stack cell flotation) was the first preference in terms of LCC while OPT 1C (belt press technology with stack cell flotation and 10% wind energy) generated the highest benefits value (BCA) compared to the other options. The LCC and BCA components and the volume of GHG emissions were used to determine the best option. Normalization of these three elements resulted in the selection of Option 1C as being the most cost-effective option.

Building condition assessment supported by Building Information Modelling

The buildings natural ageing along with the absence of planned maintenance actions and the effects of climate changes accelerate the building materials degradation. So, to extend the materials’ service life, the application of appropriate maintenance actions is imperative. This work aims to assess the building performance and to prioritize the maintenance actions employing Key Performance Indicators using Building Information Modelling-(BIM) as a supporting tool for Building Condition Assessment-(BCA) and maintenance management. To achieve these goals a methodology was proposed and applied to a case study involving 1) Building data collection; 2) Building Life Cycle Cost estimation, and 3) Automated calculation of Building Performance Indicator. This research application highlights the importance of BIM role in buildings' Facility Management, allowing the model's permanent update of information, in this case for BCA purposes. It also has high potential to prioritize the building maintenance actions, extending its materials service life, which contribute to attain a sustainable built environment.

BIM-based approach to conduct Life Cycle Cost Analysis of resilient buildings at the conceptual stage

All costs within the life cycle of a building are known as its life cycle cost (LCC). In the design process of a building, the use of a lower initial cost index to select an option among others with similar performance may not lead to an economically optimal alternative during the life cycle. Hence, today, building designers and investors require a tool to estimate life cycle cost at the conceptual design stage to select an economically efficient option. Resilient solutions generally lead to a higher level of complexity and upfront costs and carry additional embodied environmental impact as well. This study aims to support the design of resilient buildings using a sound LCC methodology in the preliminary design stage. The research aims to integrate LCC capabilities directly into a Building Information Model (BIM) and increase the economical relevance and scientific robustness of LCC indicators towards better LCC cost optimization. The plugin, which is developed in the BIM tool is represented to use cost and resiliency factors to predict the whole process cost of building projects to assist designers in selecting a cost-efficient and resilient design option. The LCC of a building includes its initial cost, repair and maintenance cost, operating cost and salvage value at the end of the building's useful life, and all of which were considered in the estimation. The earthquake expected failure and human fatality cost are calculated to consider the resiliency index in building design. The application of the proposed framework to design a residential building is developed and validated on two design options. The application of the actual building project illustrates that by increasing the initial cost in the second alternative by 4.6%, its annual expected failure cost is decreased by 35.4%, and its total life-cycle cost is reduced by almost 10.4% within the first 45 years of operation. The reduction in the cost of the building and human fatality due to failure during an earthquake means the building's resilience would be improved. Using the developed plugin, designers could estimate LCC of the buildings at the early design stages and design more resilient buildings with better economic performance in its life cycle according to the proposed indices.

A comprehensive evaluation algorithm for project-level bridge maintenance decision-making

Abstract As an indispensable process to identify the optimal treatment measures for bridge maintenance, the importance of decision-making techniques have been recently highlighted. In this paper, a multi-parameters project level bridge maintenance decision-making algorithm, conducted by the Probabilistic Neural Networks method, radial basis function method, and the Principal Component Analysis method, is investigated. A detailed study on the parameter selection, data classification, and prediction are performed by using the former two methods for the time-series index data, in terms of technical condition, average daily traffic, and sufficiency rating. The sub-item weight among different parameter indexes is calculated by the Principal Component Analysis method and evaluated by correlation evaluation. Besides, an overall evaluation model for the project level bridge maintenance decision-making is also suggested, in which the comprehensive state index model, target-based reliability model, the degradation rate factor model, and the life-cycle cost estimate and determination of maintenance time, are conducted. The optimal process is chosen and applied in three bridges as a case study. Results demonstrate that the optimal algorithm is preferable for bridge maintenance decision-making.

Life Cycle Costing in Public Building Projects in Vietnam

ABSTRACT The use of life-cycle costing in construction management is fruitful. There is an abundance of tailored, casespecific methods of LCC being developed for use in different cases or industries. However, in public buildings in Vietnam, due to the unavailability of cost, norm data and official guidance, no case of LCC use has been discovered in practice. The paper proposes an adapted approach for LCC in which life-cycle cost can be calculated as a sum of three major elements: initial construction costs, operation and maintenance costs, and the deconstruction costs. For illustration, the paper introduces a case study in calculating life-cycle cost for the Vietnam Securities Depository Centre, the first public office building being accredited as a green building under LOTUS scheme in the country. Using the same process, life-cycle costs can be calculated for other design alternatives for the building. The results are then compared to support the decision-making process to get the most viable alternative. Though this approach has some shortcomings, practitioners can find it as a step-by-step guidance for LCC; they can also use lessons learned from the case study to deal with the lack of detailed data for conducting an estimation of life-cycle costs for public buildings projects.

A digital twin architecture for effective product lifecycle cost estimation

Lifecycle cost estimation is crucial for high-value manufacturing sectors, in particular at the early product design stage, to maintain their product affordability and manufacturing profitability within the market. Accordingly, it is important to identify through-life cost reduction opportunities. However, this is a challenging task for designers at the early product lifecycle stage due to the lack of complete historical data and the existence of high-level uncertainties within the product and service cost data. Moreover, the complexity of maintenance, repair, and overhaul interventions during the operation stage reduces the designers’ decision-making confidence level at the earlier stages. This paper aims to address these challenges by proposing a novel Digital Twin (DT) architecture that uses adaptive data structure and ontologies to automatically produce the cost model from data mined information throughout a product lifecycle. The DT architecture supports designers by capturing data in terms of consumed and caused cost and automates the data flow to provide an adaptive cost estimation method across the product lifecycle. The DT enables designers to estimate the lifecycle cost at the early stage and to identify the through-life cost reduction opportunities effectively. Thereby, it is expected that the proposed DT supports OEMs to reduce the total lifecycle cost and improve the efficiency of their product development. A case study of lifecycle cost estimation in the machine tool industry is considered for testing the validity of the DT architecture.

A Markovian approach to infrastructure life‐cycle analysis: Modeling the interplay of hazard effects and recovery

AbstractProbabilistic life‐cycle cost (LCC) analysis facilitates optimal management of infrastructure systems under uncertainty. Despite recent advancements, accurate and efficient estimation of the LCC of systems facing risk of exposure to multiple stochastic occurrences of hazards has remained a significant challenge. This paper proposes a Markovian LCC framework that substantially reduces the often very high computational cost of probabilistic LCC analysis especially for large systems. The presented methodology also enhances the accuracy of LCC estimates in multiple fronts. It captures damage accumulations due to incomplete or no repair actions over multiple stochastic hazard exposures in a system's lifetime. Moreover, it tracks the state of infrastructure vulnerability during repair processes and incorporates uncertainties in downtimes associated with damage states of the system. Finally, it estimates the entirity of loss induced by a hazard and avoids the truncation error that exists in annual loss estimates for scenarios where repair downtimes are greater than one year. With these new capabilities, the proposed LCC framework is applied to a bridge in a seismic zone to estimate the LCC and analyze complex interactions of stochastic hazards and their effects with recovery efforts. Results indicate that neglecting effects of damage accumulation and partial improvements in the course of repair can lead to 20% underestimation and 14% overestimation of the expected hazard‐induced LCC, respectively.

Comparison of Product Life Cycle Cost Estimating Models Based on Neural Networks and Parametric Techniques—A Case Study for Induction Motors

The cost estimation of a product’s life cycle is a key factor in the product design process. The research is based on an innovative model of artificial neural networks (ANNs) compared to a parametric estimation. Introducing modern elements of information technologies in the area of cost estimation for a production company is a vital element of its sustainability in the era of Industry 4.0. The presented modern product life cycle cost estimation tool in the form of ANN is a reliable source of forecast that is the basis for the product life cycle cost reduction program, which is a crucial element of sustainability. Research shows that ANNs are a viable alternative to parametric cost estimation. The percentage error between estimated and historical cost values is 8.05 times lower for ANN than for the parametric approach. ANN is an adequate cost estimation model for technologically complex products. The second contribution is using technical specifications required by the customer directly to estimate the cost of a product’s life cycle automatically. This can translate both into a reduction of the time needed to provide information to the client and the workload of engineers.

A method for assessing the life cycle costs of modifications to ballasted track systems

Tests can be carried out on elements of railway track in a laboratory to assess the potential for particular ballast and sleeper combinations to alter stiffness, reduce settlement, and improve the transfer of stresses between sleeper and ballast. For example, under sleeper pads (USPs) and random fibre reinforcements (RFRs) have been shown to reduce settlement in such tests. However, it is more problematic to apply test results to predict real world field rates of deterioration along the track geometry which is largely a function of differential settlement. This is important, because an understanding of reductions in real world rates of deterioration is necessary to predict life cycle costs (LCC) of such interventions and assess the economic case for altering current practice. This research examines the impact of installing USPs and RFRs on two different routes in the UK: the London-Portsmouth line and a section of the East Coast Main Line (ECML). A simple methodology, based on relative settlement is proposed to adapt the results of laboratory element tests into a suitable parameter for input into the track geometry degradation model, allowing estimation of LCC. The financial savings from installation were found to be slightly higher for the ECML than the Portsmouth line, and higher for USPs than for RFRs. Although these conclusions are based on a UK case study, they could be applicable to any ballasted railway track operation in a developed region facing high maintenance costs and growing demand.

Natural Hazard Influence Model of Maintenance and Repair Cost for Sustainable Accommodation Facilities

To optimally maintain buildings and other built infrastructure, the costs of managing them during their entire existence—that is, lifecycle costs—must be taken into account. However, due to technological improvements, developers now build more high-rise and high-performance buildings, meaning that new approaches to estimating lifecycle costs are needed. Meanwhile, an accelerating process of industrialization around the world means that global warming is also accelerating, and the damage caused by natural disasters due to climate change is increasing. However, the costs of losses related to such hazards are rarely incorporated into lifecycle-cost estimation techniques. Accordingly, this study explored the relationship between, on the one hand, some known parameters of natural disasters, such as earthquakes, high winds, and/or flooding, and on the other hand, the data on exceptional maintenance costs, represented by gross loss costs, generated by a large international hotel chain from 2007 to 2017. The regression model used revealed a correlation between heavy rain and insurance-claim payouts. This and other results can usefully inform safety and design guidelines for policymakers, both in disaster management and real estate, as well as in insurance companies

A model to estimate the lifetime of structures located in seismically active regions

Understanding and modeling the evolution of structural systems throughout time, especially by considering its cumulative damage, is a key point for risk decision making. This concept is of extreme importance for design criteria definition, operational policies, robust life-cycle cost estimations and real time-dependent vulnerability assessment. In particular, an important objective of these type of analyses, is the estimation of the structure lifetime distribution and its corresponding mean time to failure (MTTF). However, analytic solutions of these two main concepts are not an easy task. Therefore, it is necessary to develop new approaches that can be used to better approximate the lifetime of structures in an accurate and useful way for engineering purposes. Within this context, the objective of this research work is to present a methodology to estimate the lifetime distribution of structures, and the derived properties of a structural system located in a seismic region. Mainshocks are modelled as a homogeneous Poisson process with constant mean rate of occurrence. The model, assumes that the deterioration of a given structure is mainly controlled by the cumulative damage generated by a set of consecutive earthquake events in a certain period of time. This approach can be easily implemented and provides a good estimation of the lifetime distribution of a structure, without venturing into the mathematical complexities of an analytic solution but retaining the main features of the system performance. Finally, an illustrative practical case at a real site is provided.

A Holistic Framework for Supporting Maintenance and Asset Management Life Cycle Decisions for Power Systems

The outburst of population as well as increasing industrialisation have triggered a very prominent imbalance between electricity demand and supply in emerging economies such as Indonesia. Based on this premise, electricity generation and distribution firms such as Perusahaan Listrik Negara (PLN) are faced with an urgent need to enhance availability and reliability through capacity expansion as well as the institutionalisation of cost-effective maintenance and asset management (MAM) principles. Some of the principles recommended here involve embedding customised overall health index (OHI) and total life cycle cost (LCC) estimation principles into engineering decisions that relate to asset renewal and/or replacement. While discussions about the fundamental theories and estimation approaches for OHI and LCC for power transformers (PTs) already exist in the current body of literature, however, they are mostly in a generic form which has somewhat limited proper implementation of these valuable principles in practice. This study is unique because it provides a very systematic framework towards achieving cost-effective MAM through a case study. Additionally, the proposed framework is all-encompassing, as it also assesses the impacts of human unreliability through the application or proven risk assessment techniques. The proposed framework commences with the evaluation of existing decision support system at PLN through a MAM audit, whereby the performance of the West Java arm of PLN with regards to critical MAM elements was examined.

Prognozowanie niezawodności elementów sieci wodociągowej na podstawie rzadkich danych terenowych i modeli przestrzeni stanów

The elements of critical infrastructure have to meet demanding dependability, safety and security requirements. The article deals with the prognosis of water mains reliability while using sparse irregular filed data. The data are sparse because the only thing we know is the number of mains failures during a given month. Since it is possible to transform the data into a typical reliability measure (rate of failure occurrence – ROCOF), we can examine the course of this measure development in time. In order to model and predict the ROCOF development, we suggest novel single and multiple error state space models. The results can be used for i) optimizing mains operation and maintenance, ii) estimating life cycle cost, and iii) planning crisis management.

A Super Simple Life-cycle Cost Estimation Model with Minimum Data Requirement

Life-cycle costing is a practical approach to estimate the total cost of ownership in product-service systems. In high-value manufacturing sectors, due to the complication of overhaul invoices, shop visits, repair and maintenance interventions, identifying service cost reduction opportunities can be complex. Moreover, quantifying the impact of key cost drivers on the total cost is challenging due to the lack of complete historical data and high level of uncertainties within the service cost data. To address these challenges, a super simple life-cycle cost model architecture is presented. A set of minimum data requirements is identified for the development of the presented cost model. The model architecture comprises of life-cycle cost breakdown structure and work breakdown structure to specify the cost drivers, unit costs and their frequencies. A bottom-up activity-based cost estimation approach is implemented to calculate the total life-cycle cost of a product. The way that the minimum data requirement is applied to the cost estimation structure is explained. In addition, the minimum data is employed to perform a deterministic sensitivity analysis to compare the relative impact of the model input on the total cost. The Monte-Carlo simulation is performed for estimating the uncertainty propagation on the total life-cycle cost. The presented model architecture simplifies life-cycle cost estimations and service control decisions for maintenance, repair, and overhaul actions. A case study of life-cycle cost estimation in the machine tool industry is considered for testing the validity of the cost model architecture.