Life Cycle Cost Estimation Research Articles

Probabilistic pre-estimation of life-cycle costs of road bridges using dynamic Bayesian networks

Proper life-cycle cost (LCC) estimation of vital transportation network assets, such as road bridges, is crucial for cost-efficient projects. This study presents a probabilistic framework for the LCC estimation of concrete bridges based on Dynamic Bayesian Network (DBN) modelling that stakeholders can consult in projects’ preliminary stages for suitable decision-making. The proposed model consists of two separate modules. The first accounts for the probabilistic estimation of material quantities and their relative costs during the construction phase, specifically for the bridge’s superstructure and foundation. The second one refers to the operational phase of the bridge’s components. For illustrative purposes, the maintenance costs of deck expansion joints are presented, as they are regarded as vulnerable bridge components with regular repairs. The suggested DBN includes time-dependent and continuous variables thoroughly documented over multiple time stages. The DBN is formulated using actual records of 78 concrete bridges’ construction, deterioration, inspections and maintenance from the Egnatia Odos motorway in Greece. The presented approach is an effective tool for bridge management enhancement owing to stochastic dynamic interdependencies among parameters and continuous information updating.

Intersection Control Evaluation for Highway Safety Analysis

Road traffic accidents take more lives than a combination of other accidents and natural disasters. An article published on September 9, 2023, in the Nepali Times, reported that between April 2022 and April 2023, a total of 2,320 individuals lost their lives, with 28,856 sustaining injuries, many resulting in lifelong impairment. Traffic studies have revealed that Intersection Control Evaluation (ICE) facilitates strategic decision-making through the use of factual information, data, and metrics. The primary objective of this research on intersection control evaluation is to explore how the screening process and the selection of alternative intersections in ICE contribute to the reduction of accidents at intersections. A focused examination of the literature assessing the methodology's effectiveness in maintaining intersection safety suggests that intersection control evaluation aids in strategy selection during expansion and signal usage at major intersections. Subsequent discussions utilized various spreadsheet tools and online forums. The findings indicate that ICE serves as an effective framework for screening intersection alternatives and identifying optimal solutions. Results show that tools such as 'Capacity Analysis for Planning of Junctions' (CAP-X) effectively evaluate intersection types. Additionally, 'Safety Performance of Intersection Control Evaluations' (SPICE) is employed for safety analysis at grade intersections. Cost analysis, based on results obtained from the Life Cycle Cost Estimation Tool (LCCET) spreadsheet, demonstrated the cost-effectiveness of this approach.In light of the results and discussions, intersection control evaluation should play a crucial role in implementing safer, more balanced, and cost-effective solutions at road intersections.

An analytical approach to evaluate life-cycle cost of deteriorating pipelines

Optimal inspection and maintenance planning for deteriorating pipelines is important for cost-effective risk management decisions. The objective of this study is to develop an analytical approach for determining the expected value and standard deviation of life-cycle cost (LCC) for deteriorating pipelines, which can incorporate imperfect repair and inspection actions without making independent assumptions of failure and repair events. The framework is developed based on a decision tree model by using analytical methods to evaluate events and considers the impact of the inspection schedules and possible repair actions on the probability distributions of failure times. To illustrate the proposed framework, a steel transmission pipeline with a corrosion defect is used, where a stochastic model of corrosion growth is assumed and burst failure is considered as the pipeline failure mode. The case study indicates that the failure cost due to two or more failure occurrences can be ignored; and the inspection interval, repair threshold and type, the length of lifetime considered, and unit failure cost all play important roles in the expected value of the total cost. The variation in the LCC estimation is found to be significant, and it has a great impact on determination of optimal decision variables.

ESS가 포함된 태양광 발전의 생애주기 비용추정 사례 연구

ESS가 포함된 태양광 발전의 생애주기 비용추정 사례 연구

Life Cycle Cost Estimation and Analysis of Transformers Based on Failure Rate

Transformers, as the hub equipment of the power system, are highly valued by engineering and scientific researchers in production practice and scientific research. The goal of transformer research is to ensure the safe operation of transformers while considering their economic benefits, arrange transformer inspections reasonably to reduce inspection costs, and save labor and maintenance costs reasonably. This study first provides a brief analysis of the life cycle cost of transformers. The life cycle of transformers is divided into initial cost, operating cost, maintenance cost, fault cost, and scrap cost. Based on the distribution of transformer failure rate, the corresponding life cycle cost of transformers is calculated. Taking 110 kV transformers as an example, the differences in the impact of key factors on the full life cycle cost are analyzed to achieve high quality, high reliability, economically optimal equipment procurement.

Life Cycle Costing for Structural Analysis and Design

As the construction sector is a major contributor to the environmental pressures and impacts that are accelerating the climate crisis, there is an increasing focus on sustainability, adoption of innovative technologies and materials. The European Commission (EC) already in 2019 with the Green Deal recommended also in the construction sector the use of life cycle approaches to promote materials and strategies aimed at the transition to the circular economy (CE).In this context, Life Cycle Costing (LCC) is one of the successful techniques to identify the total cost of construction goods. Life cycle engineering has emerged as an effective approach to improve product and material design, to reduce maintenance and to contain whole life costs. Therefore, it is increasingly necessary to use both technical and economic evaluation approaches when selecting investments in order to contain the overall costs for the decision-maker until the project is decommissioned. Although this technique has around 50 years of history, its application and diffusion in the construction sector is still relatively limited.This paper first provides an overview of existing research on the Life Cycle-based approach for the economic evaluation of new structural materials and civil infrastructure systems. Then, LCC-based methodology is defined to assess and compare the structural and economic performance of civil engineering constructions. The logical-operational steps on which the analysis approach is based concern: (i) structural analysis of buildings; (ii) estimation of life-cycle costs; (iii) evaluation of the ‘Global Cost’ economic indicator; (iv) comparison of the economic and structural performance of design alternatives. This approach allows the designer to choose the material with the lowest life-cycle cost for the same mechanical and technical characteristics. In general terms, the use of such a methodology enables effective investment choices and can be a valuable support in the field of civil engineering whenever it is necessary to identify the most cost-effective of several structural alternatives.Research prospects concern the validation of the model through its application to case studies. It is also envisaged extending the study to the assessment of the environmental and social impacts arising from design alternatives.

Life-cycle cost estimation of a building structure: An example of partition walls

Abstract The growing pressure to optimise construction investment costs from the life-cycle perspective inevitably leads to efforts to seek new solutions that will facilitate informed decision-making in the early stages of the construction project. Awareness of the importance of considering future operation and demolition costs emphasises the shortcomings related to the possibility of making accurate predictions/estimations of such costs, which will become apparent in the future. To address this research gap, an innovative approach of life-cycle cost modelling on the level of individual structures of the building is presented. The model provides users with information on the costs of available technical solutions resulting from the requirements of the investor at a specific stage of the construction project. In this way, it helps investors optimise their building projects and to find the most economical solutions. Specifically, this model is assembled for the purpose of selecting a suitable partition wall and, therefore, it takes into consideration specific characteristics relating to this particular type of structure. The results indicate diversity in partition wall structural design variants at the early stage of the project. Since the ability to influence future costs decreases as the project progresses, the model allows capturing LCC perspective even if only a construction study is available without more detailed technical and economic information. The presented model aims to contribute to the higher performance of construction projects in the planning phase from the perspective of LCC and investors’/owners’ point of view.

Modeling Shipboard Power Systems for Endurance and Annual Fuel Calculations

_ Endurance fuel calculations are used to determine the required volume of fuel tanks; annual fuel calculations are used to estimate the fuel consumed during a year of ship operations, primarily to estimate the projected cost of fuel as part of the life cycle cost estimate. These calculations depend on the fuel rates (kg/h) for different electrical and propulsion system configurations. The fuel rates in turn depend on factors, such as equipment efficiency, prime mover-specific fuel consumption curves, electrical loads, ambient temperature, propulsion loads, and the manner in which the power and propulsion systems, are operated. This paper details how to perform endurance fuel and annual fuel calculations, provides guidance for modeling system components based on data typically provided in data sheets, and provides guidance on the manner in which the power and propulsion systems are operated. Four examples are provided to illustrate the methods using the Smart Ship System Design modeling and simulation tool along with supporting spreadsheets. Keywords Marine design for ships and offshore structures; endurance; fuel efficiency; electrical efficiency; electrical system; performance prediction

EFFICIENCY OF INVESTMENT PROJECTS OF URBAN CAPITAL CONSTRUCTION OF REAL ESTATE IN MODERN ECONOMIC CONDITIONS

The main methods for assessing the effectiveness of investment projects of urban capital construction of real estate in modern economic conditions in the presence of inflationary processes are discussed. It shows a fundamental change in approaches to assessing the effectiveness of real estate of state property, which is associated with the cost of designing, construction, maintenance and operation of facilities, including their disposal, as well as received benefits or income, taking into account inflationary processes that exist in the modern Ukrainian economy. The analysis of the cost and expenses of the real estate object was carried out in the framework of its life cycle concept. The basic informational and methodical problems are shown and the ways of their solution concerning the introduction in Ukraine of the reasonable scientific method of the life cycle cost estimation when creating and operating the real estate objects of city capital construction which are in the state property are offered.

Life-cycle benefits estimation of self-centering building structures

Various self-centering structural systems were developed and investigated for reducing residual inter-story drifts of the traditional aseismic structural system by achieving full or partial self-centering behaviors under earthquakes in the past twenty years. However, limited research was conducted to investigate the life-cycle benefits of the full and partial self-centering structural systems on the life-cycle span, figuring out a more cost-effective solution for enhancing the building’s seismic resilience. This paper aims to comprehensively investigate the life-cycle benefits of full and partial self-centering structural systems compared to conventional buckling-restrained braced frames (BRBFs) using the life-cycle cost estimation method. The influences of the residual inter-story drift limit for demolition, the initial cost of emerging self-centering members, the value of building contents, and the discount rate were particularly investigated. To this end, three building structures with BRBFs and full and partial self-centering structural systems were designed to achieve the same capacity for controlling maximum inter-story drifts. Comprehensive dynamic analyses were performed to generate engineering parameters under different seismic intensities and the modeling uncertainties were properly considered through Monte Carlo simulation. The revised HAZUS loss calculation method was adopted to investigate the seismic annual loss (SAL) and life-cycle cost. The analysis results indicate that the partial self-centering behavior would be a better choice than the full self-centering behavior for developing the self-centering structural systems to achieve better life-cycle benefits. Moreover, it is essential and urgent to reduce the initial costs of self-centering structural members and control the floor acceleration responses for increasing the life-cycle benefits of self-centering structural systems and promoting their practical applications.

Simplified Life Cycle Cost Estimation of Low-Rise Steel Buildings Using Fundamental Period

In the current study, a simplified seismic life cycle cost (LCC) estimation procedure is proposed utilizing the mean values of the structure’s main input variables. The main input variables of the building are used for constructing a relationship between the structural fundamental period (T) and an average estimation of the LCC (LCCavg). Using the actual building properties related to damage probability, the T–LCCavg relationship is used to obtain the final LCC (LCCfin). The equivalent single degree of freedom (ESDOF) model and SAC-FEMA framework are utilized for damage probability calculation. The dispersion measure in demand is approximately calculated based on the mean plus one standard deviation of the seismic hazard response spectrum, and, then, verified through nonlinear time history (NLTH) analyses of the original structure. Five and three-story steel buildings are used as case studies for verification of the proposed method. The analysis results indicate that the proposed procedure provides reasonable LCC estimations for low-rise buildings dominated by the fundamental mode of vibration.

Smart photovoltaic system for Indian smart cities: a cost analysis.

In this paper, a methodology and optimization using the artificial bee colony (ABC) algorithm for life cycle cost (LCC) assessment of photovoltaic (PV) system for some Indian smart cities have been presented. Smart cities are the urban areas that utilize solar power PV system with other advanced innovations. The life cycle cost with and without carbon credit earned due to solar power generation in particular smart city should be known. Smart cities aim to assist local bodies in assessing their present energy consumption and future demand. This paper also focuses on PV energy generation, savings, and efficiency with cost. Four smart cities have been selected for LCC estimation on different field condition basis. The results show that in Srinagar, energy production is maximum, i.e., 435MWh, and LCC is minimum INR4125 million with an 8.9% rate of return on it. Therefore, net carbon dioxide emission reduction per annum for smart PV system over a lifetime of 20years is 76.5 tCO2e on the overall thermal energy and 17.7 tCO2e on the overall exergy gain. LCC of smart PV system for different years has been estimated and optimized using the ABC algorithm, and the results show a 50.24% reduction in LCC. With the proposed approach, future opportunities for smart cities with smart PV system can be revealed.

Meta heuristic intelligent decision support model for uncertainty estimation of life cycle cost in railways rolling stock

In Railways rolling stock, Rate of Occurrence of Failures (ROCOF) of repairable components is time varying and has a failure trend, so the combined process of Reliability, Availability, Maintainability and Safety (RAMS) with Life Cycle Cost (LCC) is a stochastic process. Heuristic approaches have been used to design intelligent decision support model to reduce Life Cycle Cost (LCC) and to manage Maintainability to achieve the required Reliability. As heuristic approaches have major drawback of inability to combine both the exploration and exploitation capabilities to reach all regions in the search space, so we propose Meta heuristic approach by hybridization Particle Swarm Optimization (PSO) and Genetic Algorithm (GA). Experimental study proves that our proposed approach significantly avoids this drawback and outperforms the traditional heuristic approaches in reducing LCC while properly maintains the required reliability.

A Robust Design for Lifecycle Cost with Reliability Analysis Integration

Maintenance, repair, and overhaul (MRO) is the most significant cost driver over a complex engineering asset lifecycle. Therefore, high-value manufacturers are required to plan MRO occurrences to optimize the overhaul cost while achieving the desired performance. This trade-off imposes a shift towards a proactive maintenance strategy. However, creating a long-term proactive maintenance plan is challenging due to uncertainties in the performance of the asset and its critical components. Hence, this paper presents a robust design framework for the lifecycle cost estimation process by integrating reliability life data analysis. The level of data availability across the lifecycle is considered. The framework is proposed based on a literature review and the Delphi method. This study highlights that the level of robustness in the lifecycle cost estimates can be achieved by continuous feedback to the design phase and to the body of knowledge over the asset lifecycle. Moreover, this study suggests that the optimization model for the trade-off between cost and reliability should fulfil safety and environmental sustainability requirements when providing a cost-effective reliability solution.

BIM dimensions: example of air blower station at wastewater treatment plant

The main goal of research is to analyse the prospects for the development of BIM dimensions (3D-7D) in Russia on the example of Water and wastewater industry (WWI) asset. Justification of goal is the insufficient development of industry-specific BIM systems, allowing for different interpretations of its dimensions. The object of research is the air blower station (ABS), the most energy-intensive asset, which typically consumes 62-85% of the energy of WWTP’s. The method is a hypothesis of 3D-7D modeling of water utility asset, presented for the discussions. ABS compressors reduce costs by regulating the air supply due to lifestyle of the population and seasonal environmental conditions (example of simulation results is present). 3D design visualises variant of the reconstruction of the ABS, implemented according to typical project. 4D planning represent the schedule of energy service company, which provides investments and jobs for: design documentation execution, equipment purchase, installation and commissioning of equipment. 5D costs analyses features of the phase in terms of project expertise. 6D sustainability model in practice differs from prediction or forecasting generated by the simulation model of ABS asset, power consumption will be lower up to real (not simulated) technological loads. 7D management analyses possibility of the life cycle cost estimation as strategic advantage of WWI standard. The paper is based on Russian standards. Designing of 3D models are developing on an irregular basis (proactively) in Russia. The mastering of modeling 3D, 4D, 5D based on individual disciplines (as autonomous databases) is self-sufficient today as WWI tusk. The operational nature of WWI enterprises testifies to the development of elements of 6D-7D models.

Asset Management Framework and Tools for Facing Challenges in the Adoption of Product-Service Systems

Servitization is recognized as a key business strategy for original equipment manufacturers willing to move up the value chain. However, several barriers have to be overcome in order to successfully integrate products and services. Many of these barriers are caused by the technical challenges associated with the design and management of the product-service systems (PSSs), such as life cycle service level and cost estimation, risk management, or the system design and pricing. Asset management (AM) presents itself as a key research area in order to overcome these barriers as well as to integrate PSSs within the manufacturers’ operations management. It is the scope of this article to provide theoretical and practical insights with regards to the alignment of AM and PSS research areas. To support the alignment between both areas, a management framework which gathers specific technologies, including reliability analysis, simulation modeling, and multiobjective optimization algorithms, is presented. The purpose of the framework is to provide manufacturers with a decision-support tool that facilitates the main managerial challenges faced when implementing a servitization strategy. The article contributions are successfully applied to case studies in the railway and wind energy sectors based on real field data, thereby demonstrating their suitability for both facilitating manufacturer’s decision-making process and better satisfying stakeholders’ interests.

Agri-Biodegradable Mulch Films Derived from Lignin in Empty Fruit Bunches

Mulch films increase soil temperature, maintain soil moisture, improve water and fertilizer absorption, and reduce weed growth. This work studied a mulching film made using polyvinyl alcohol (PVA) and lignin extracted from empty fruit bunches (EFBs). The mulch films were investigated for opaqueness, biodegradation, water-solubility, absorption, and mechanical properties. Life cycle assessment (LCA) and cost estimate analysis were conducted. The composite mulch film-PVA solution was blended with 6% EFB lignin in dimethyl sulfoxide (DMSO) solution using five different amounts (0, 20, 40, 60, or 80 wt% lignin). The results showed that increasing the amount of lignin increased the film’s water solubility, moisture content, and biodegradability. At the same time, water absorption tended to decrease. Consequently, the light transmittance of the film was reduced, which had a positive effect on preventing soil weed growth. Tests of the mechanical properties showed that 60% lignin in the PVA film had the highest tensile strength (16.293 MPa). According to the LCA studies and cost estimation, the lignin-mixed PVA film had the lowest impact and was cheaper than the commercial mulching film. The results suggested that it is possible to blend polyvinyl alcohol polymer with lignin to improve biodegradability up to 25.47% by soil burial and 32% by water solubility.

Cost Analysis of Synchronous Condenser Transformed from Thermal Unit Based on LCC Theory

With the development of large-scale renewable energy consumption and multi-infeed high voltage direct current (HVDC) systems, the demand of a system for the synchronous condensers with a strong dynamic reactive power support capacity and a strong short-time overload capacity is increasing. Meanwhile, with the reuse of a large number of retired thermal units, the most practical and economic way is to transform thermal units into synchronous condensers. The cost difference in the life-cycle of the synchronous condenser transformed from a thermal unit (SCTTU) and the newly established synchronous condenser (NESC) is a key factor that affects the decision-making and construction of the transformation from thermal unit to synchronous condenser. However, the life-cycle cost (LCC) of the synchronous condenser transformed from a thermal unit and the newly established synchronous condenser contains many uncertain factors, which affect the accuracy of the LCC estimation value. In order to quantify the impact of the blind information on the cost of the synchronous condenser station, blind number theory is introduced to establish the blind number model of the LCC of the synchronous condenser transformed from a thermal unit and the newly established synchronous condenser. Additionally, the LCC of the NESC and SCTTU with a different life-cycle under the capacity of 2 × 300 MVar are estimated. The results show that the cost of the SCTTU with a long service life of more than 15 years is significantly lower than that of the NESC and, thus, the SCTTU has better economic performance. The economic performance of the SCTTU with a life-cycle of less than 15 years is not better than that of the NESC. Compared with the traditional calculation method of a single cost value, the blind number model can obtain the possible distribution interval of LCC and the reliability of the corresponding interval, which makes the estimation results more valuable for practical engineering reference.

Designing a Framework for Bidding and Estimating Life Cycle Cost in Indian Defence Sector: A Systematic Approach

Lifecycle Management (LCM) is the process of managing the entire lifecycle of products or services right from the inception (design, manufacture, supply) stage to the maintenance and disposal oSf products. It integrates the people, data, processes and business systems and provides product information backbone for enterprises and their extended units. LCM in the defence sector is a very critical and complex process. This is specifically mandated in the operational framework defined by the Government of India at the proposal stage itself. The main objective of the current study is to identify the various challenges being experienced by the companies in executing LMC, especially in the defence sector and critically examine various methods and practices of the bidding system. Crafting a strategy for participating companies, in defence projects in India and winning them, is considered a difficult task. This study evaluates the international best management practices and applies the maturity model for contract management as being practised in the Netherlands. This maturity model consists of a model for the identified tactical level and operational level in contract management. These two models can help an organisation to determine their ‘as is’ situation and structured review system, identify key factors those having influence on the optimal level found in this process, and their ‘to be’ situation. The current research also proposes a review gates system to enable organisations to facilitate a systematic approach in analysing any project opportunity in the context of the procurement life cycle as per guidelines and policies defined by Defence Procurement Procedures (DPP), Government of India. Additionally, a detailed framework has been suggested to generate and maintain agreed cost estimates within the wider business context.

Systematic data-driven exploration of Austrian wastewater and sludge treatment - implications for phosphorus governance, costs and environment

Within the new policy framework shaped by the EU Green Deal and the Circular Economy Action Plans, the field of wastewater and sludge treatment in Europe is subject to high expectations and new challenges related to mitigation of greenhouse gas emissions, micropollutant removal and resource recovery. With respect to phosphorus recovery, several technologies and processes have been thoroughly investigated. Nevertheless, a systemic and detailed understanding of the existing infrastructure and of the related environmental and economic implications is missing. Such basis is essential to avoid unwanted consequences in designing new strategies, given the long lifespan of any infrastructural change. This study couples a newly collected and highly detailed database for all wastewater treatment plants in Austria bigger than 2000 population equivalent with a combination of analyses, namely Substance Flow Analysis with focus on nutrient and metal distribution in different environmental and anthropogenic compartments, Energy Flow Analysis, Life Cycle Assessment and cost estimation. The case study of Austria is of special interest, given its highly autonomous administration in federal states and its contrasting traits, ranging from flat metropolitan areas like Vienna to low-populated alpine areas. The significant impact of electricity demand of wastewater treatment on the overall Cumulative Energy Demand (CED) shows the importance of optimization measures. Further, the current system of wastewater and sludge disposal have a low efficiency in recovering nutrients and in directing pollutants as heavy metals into final sinks. Sludge composting with subsequent use in landscaping does not only show an unfavorable environmental balance, but it is the only relevant route leading to additional CED and Global Warming Potential emissions and to the highest transport volume. Altogether, the outcomes of this study provide a sound basis to further develop national strategies for resource recovery aimed to optimize trade-offs between different economic and environmental objectives.