Life Cycle Cost Model Research Articles

A total life cycle cost model (TLCCM) for the circular economy and its application to post-recovery resource allocation

The consumerism-driven, consumption-based linear economy is leaving a trail of economic, environmental, and societal challenges in its wake. The Circular Economy, a new economic framework, can be combined with the 6R-based elements of sustainable manufacturing in order to relieve these challenges by establishing a closed-loop material flow. To realize this ideal state, a total life cycle cost model (TLCCM) is needed to serve as the primary engineering economic model. Therefore, a framework for such a model is presented that aims to aid stakeholders in making decisions regarding all aspects of the product life cycle. It is intended that these stakeholders use this model in order to challenge the status quo of costly “green”-centric decisions and demand innovation in the overall process in order to realize a net positive total life cycle cost benefit alongside a balanced Triple-Bottom-Line (TBL). To illustrate how the TLCCM can be applied, an application is explored that uses the model to determine post-recovery resource allocation into three closed-loop streams (Recycling, Remanufacturing, and Reusing). An outlook for future research is then presented.

Selecting composite materials considering cost and environmental impact in the early phases of aircraft structure design

Abstract The main aim of this study is to develop a computer-aided material selection tool that supports the designer in the selection of the most suitable carbon fiber-reinforced composite configuration (orientations, the number of plies, material type) for aircraft structures. The selection procedure is based on technical, economic and environmental performance objectives for a given design, in a multidisciplinary and multi-objective optimization scenario. Economic and environmental performance evaluation is based on an integrated Life Cycle Assessment (LCA)/Life Cycle Costing (LCC) model. Technical performance evaluation is done using Hypermesh-Optistruct® solver. Direct multi-search (DMS) solver is used for the optimization framework. A cargo aircraft elevator design is optimized using the proposed material selection tool. Results show that the material selection tool is a suitable guide for reducing weight during the early phases of design and promoting sustainable development in the aircraft industry.

Derivation of Life Cycle Cost Model for Selecting Optimum Decisions in Engineering Asset Management

It is common that interdepartmental conflict may arise in an organisation to select which decision to be taken, especially in the area of engineering asset management. In this paper, an engineering asset management related case study is discussed and a derivation of a life cycle cost model is proposed to assist finding the optimum decision. Another challenge in this study is a situation that the data and information required to calculate the total cost is unavailable. To deal with this situation, a cost comparison approach is proposed as well as a sensitivity analysis in order to select the optimum decision if the uncontrolled variable in the system nature changes. The result shows that the total cost model derived from the life cycle cost model is capable to assist selecting the optimum decision. A simple spreadsheet based Monte Carlo model is also developed to represent the randomness of the time to failure during the five years of time horizon of the analysis.

Environmental and financial performance evaluation of a helicopter’s canopy production using different materials and manufacturing processes

In the present work Life Cycle Analysis (LCA) and Life Cycle Costing models (LCC) were developed for quantifying the financial and environmental performance of different material (carbon fiber reinforced thermosetting and carbon fiber reinforced thermoplastic composites) and manufacturing scenarios (autoclave, RTM and CDF) associated with the production of aeronautical structural components. To validate the models developed, they were implemented for the case of a helicopter’s canopy. The results from the analysis pointed out the environmental and financial 1advantage of producing the canopy from carbon fiber reinforced thermosetting composites involving RTM as the manufacturing process. On the other hand, the environmental and financial viability of the scenarios including thermoplastic composites as the material of choice is impaired from both the high embodied energy and raw material cost of PEEK. However, potential benefits from thermoplastic composites like recyclability and reusability as well as the high production rates that they offer and not taken into account in this study could improve their environmental and financial viability. This underlines the need to include potential reusing and recycling applications of the composites, as well as circular economy considerations to the criteria for designing an aircraft structure, selecting the material for this structure and finally manufacturing the structure.

Life cycle assessment and cost analysis evaluation of a helicopter's canopy production using different manufacturing processes

In the present work, Life Cycle analysis (LCA) and Life cycle costing (LCC) models were developed in order to quantify the environmental footprint and cost and thus compare different manufacturing scenarios associated with the production of aeronautical structural components. To validate the models developed, they were implemented for the case of a helicopter's canopy processed by two techniques commonly used in aeronautics, namely the autoclave and the Resin Transfer moulding (RTM). The canopy was assumed to be made of a carbon fiber reinforced thermosetting material. Using the models developed the expected environmental and cost benefits by involving the RTM technique have been quantified.

A rationale for choosing the mechanism of public-private partnership for the sustainable development of social infrastructure facilities

Using the mechanism of public-private partnership (PPP) is an effective way to attract investment for the modernization of urban infrastructure in the face of budget shortfalls, which is especially important for the sustainable development of the social infrastructure of the territories. The aim of the study is to analyze the models of public-private partnership (PPP) and substantiate the choice of the model to ensure sustainable development of the social sphere. The life-cycle cost (LLC) model is represented as the most effective one for realizing municipal facilities development projects.

On design criteria for a disconnectable FPSO mooring system associated with expected life-cycle cost

ABSTRACTSome floating production, storage and offloading units (FPSOs) possess disconnectable systems to avoid harsh environments. According to a literature survey, the practice is based on perceptions and experiences of operators to judge disconnection; however, this paper offers a rational approach. A life-cycle cost model is proposed to optimise (1) the disconnection criteria and (2) the design of mooring lines under reliability format. Relevant ultimate limit states are considered in association with hull, moorings and green water failure. Effects of future failure costs are considered (downtime, environmental damage, reputation, etc.). Disconnection criteria are then formulated in terms of significant wave height and wind speed limits. Because a permanent mooring system may exhibit excessive resistance, it is possible to reduce the lines’ thickness until the cost is optimised for non-permanent service. Results for an example in the Gulf of Mexico show that important savings can be achieved by implementing the proposed optimisations.

Dimensioning reserve bus fleet using life cycle cost models and condition based/predictive maintenance: a case study

The paper demonstrates the dependence of a fleet reserve of buses on the maintenance policy of the whole fleet, in particular, condition-based maintenance using a motor oil degradation analysis. The paper discusses an approach to evaluate the oil degradation and the prediction of the next value for one relevant oil variable. The methodology to evaluate the reserve fleet is based on bus availability, estimated through the mean time between failures and the mean time to repair ratios. Through the use of econometric models, it is possible to determine the most rational size of the reserve fleet.

Multi-Objective Optimization of a Hybrid ESS Based on Optimal Energy Management Strategy for LHDs

Energy storage systems (ESS) play an important role in the performance of mining vehicles. A hybrid ESS combining both batteries (BTs) and supercapacitors (SCs) is one of the most promising solutions. As a case study, this paper discusses the optimal hybrid ESS sizing and energy management strategy (EMS) of 14-ton underground load-haul-dump vehicles (LHDs). Three novel contributions are added to the relevant literature. First, a multi-objective optimization is formulated regarding energy consumption and the total cost of a hybrid ESS, which are the key factors of LHDs, and a battery capacity degradation model is used. During the process, dynamic programming (DP)-based EMS is employed to obtain the optimal energy consumption and hybrid ESS power profiles. Second, a 10-year life cycle cost model of a hybrid ESS for LHDs is established to calculate the total cost, including capital cost, operating cost, and replacement cost. According to the optimization results, three solutions chosen from the Pareto front are compared comprehensively, and the optimal one is selected. Finally, the optimal and battery-only options are compared quantitatively using the same objectives, and the hybrid ESS is found to be a more economical and efficient option.

Life-cycle impacts of shower water waste heat recovery: case study of an installation at a university sport facility in the UK.

Recovering heat from waste water discharged from showers to preheat the incoming cold water has been promoted as a cost-effective, energy-efficient, and low-carbon design option which has been included in the UK's Standard Assessment Procedure (SAP) for demonstrating compliance with the Building Regulation for dwellings. Incentivized by its carbon cost-effectiveness, waste water heat exchangers (WWHX) have been selected and incorporated in a newly constructed Sports Pavilion at the University of Brighton in the UK. This £2-m sports development serving several football fields was completed in August 2015 providing eight water- and energy-efficient shower rooms for students, staff, and external organizations. Six of the shower rooms are located on the ground floor and two on the first floor, each fitted with five or six thermostatically controlled shower units. Inline type of WWHX were installed, each consisted of a copper pipe section wound by an external coil of smaller copper pipe through which the cold water would be warmed before entering the shower mixers. Using the installation at Sport Pavilion as the case study, this research aims to evaluate the environmental and financial sustainability of a vertical waste heat recovery device, over a life cycle of 50years, with comparison to the normal use of a PVC-u pipe. A heat transfer mathematical model representing the system has been developed to inform the development of the methodology for measuring the in-situ thermal performance of individual and multiple use of showers in each changing room. Adopting a system thinking modeling technique, a quasi-dynamic simulation computer model was established enabling the prediction of annual energy consumptions under different shower usage profiles. Data based on the process map and inventory of a functional unit of WWHX were applied to a proprietary assessment software to establish the relevant outputs for the life-cycle environmental impact assessment. Life-cycle cost models were developed and industry price book data were applied. The results indicated that the seasonal thermal effectiveness was over 50% enabling significant energy savings through heat recovery that led to short carbon payback time of less than 2years to compensate for the additional greenhouse gas emissions associated with the WWHX. However, the life-cycle cost of the WWHX is much higher than using the PVC pipe, even with significant heat recovered under heavy usage, highlighting the need to adopt more economic configurations, such as combining waste water through fewer units, in order to maximize the return on investment and improve the financial viability.

Integration of RAMS in LCC analysis for linear transport infrastructures. A case study for railways.

Life-cycle cost (LCC) analysis is an economic technique used to assess the total costs associated with the lifetime of a system in order to support decision making in long term strategic planning. For complex systems, such as railway and road infrastructures, the cost of maintenance plays an important role in the LCC analysis. Costs associated with maintenance interventions can be more reliably estimated by integrating the probabilistic nature of the failures associated to these interventions in the LCC models. Reliability, Maintainability, Availability and Safety (RAMS) parameters describe the maintenance needs of an asset in a quantitative way by using probabilistic information extracted from registered maintenance activities. Therefore, the integration of RAMS in the LCC analysis allows obtaining reliable predictions of system maintenance costs and the dependencies of these costs with specific cost drivers through sensitivity analyses. This paper presents an innovative approach for a combined RAMS & LCC methodology for railway and road transport infrastructures being developed under the on-going H2020 project INFRALERT. Such RAMS & LCC analysis provides relevant probabilistic information to be used for condition and risk-based planning of maintenance activities as well as for decision support in long term strategic investment planning.

Economic Viability Analysis of Silicon Solar Cell Manufacturing: Al-BSF versus PERC

The International Technology Roadmap for Photovoltaic (ITRPV) predicts that the worldwide market share of the PERC silicon solar cell technology will grow to about 40% by 2021. In line with this forecast, several solar companies have announced new investments into manufacturing capacity for PERC cells. Though higher in terms of efficiency, the economic success of the PERC technology - against the incumbent Al-BSF technology - is strongly dependent on the $/Wp cost to manufacture it. Moreover, currently the solar cell industry is dominated by p-type multi-Si BSF cell technology, due to the historically lower cost of block-cast multi-Si wafers compared to crystalline Cz mono-Si wafers. Recently there has been a sharp decline in the cost of mono-Si wafers, making mono-Si cells more cost-competitive to multi-Si cells. We use a comprehensive life-cycle cell cost model, developed in SERIS, to calculate break-even $/Wp to manufacture p-type multi-Si Al-BSF and PERC cells. The model takes into account the total life-cycle cost of a 1-GWp production capacity operating for seven years, including manufacturing cost (e.g. consumables, O&M) and financing cost. The output data aligns well with the historical trend in the ITRPV, and thus the model was expanded to compare the $/Wp cost of manufacturing p-type multi-Si and mono-Si PERC cells. Our calculations indicate that cost to manufacture p-type multi-Si PERC cells is ~0.7 $-cents/Wp higher than p-type multi-Si BSF cells. The increase in cost is primarily due to additional processing steps requiring higher capital and labor cost, but partially compensated by the lower $/Wp costs of the wafers and the silver. The break-even cost of p-type mono-Si PERC cells is ~ 2.3 $-cents/Wp higher than for p-type multi-Si PERC cells, due to the higher cost of the input wafers.

Environmental and Economic Implications of Distributed Additive Manufacturing: The Case of Injection Mold Tooling

SummaryAdditive manufacturing (AM) holds great potentials in enabling superior engineering functionality, streamlining supply chains, and reducing life cycle impacts compared to conventional manufacturing (CM). This study estimates the net changes in supply‐chain lead time, life cycle primary energy consumption, greenhouse gas (GHG) emissions, and life cycle costs (LCC) associated with AM technologies for the case of injection molding, to shed light on the environmental and economic advantages of a shift from international or onshore CM to AM in the United States. A systems modeling framework is developed, with integrations of lead‐time analysis, life cycle inventory analysis, LCC model, and scenarios considering design differences, supply‐chain options, productions, maintenance, and AM technological developments. AM yields a reduction potential of 3% to 5% primary energy, 4% to 7% GHG emissions, 12% to 60% lead time, and 15% to 35% cost over 1 million cycles of the injection molding production depending on the AM technology advancement in future. The economic advantages indicate the significant role of AM technology in raising global manufacturing competitiveness of local producers, while the relatively small environmental benefits highlight the necessity of considering trade‐offs and balance techniques between environmental and economic performances when AM is adopted in the tooling industry. The results also help pinpoint the technological innovations in AM that could lead to broader benefits in future.

A multi-objective optimisation approach applied to offshore wind farm location selection

This paper compares the three state-of-the-art algorithms when applied to a real-world case of the wind energy sector. Optimum locations are suggested for a wind farm by considering only Round 3 zones around the UK. The problem comprises of some of the most important techno-economic life cycle cost-related factors, which are modelled using the physical aspects of each wind farm location (i.e., the wind speed, distance from the ports, and water depth), the wind turbine size, and the number of turbines. The model is linked to NSGA II, NSGA III, and SPEA 2 algorithms, to conduct an optimisation search. The performance of these three algorithms is demonstrated and analysed, so as to assess their effectiveness in the investment decision-making process in the wind sector, more importantly, for Round 3 zones. The results are subject to the specifics of the underlying life cycle cost model.

Evaluation of energy retrofit in buildings under conditions of uncertainty: The prominence of the discount rate

A growing literature has focused on the economic viability of energy retrofit in buildings. As regards the valuation tools, the Life-Cycle Cost (LCC) method has established itself among the leading approaches. The results are usually affected by a core of influential, uncertain parameters: energy supply cost and energy price changes. Monte Carlo (MC) simulation may be integrated with LCC analysis to deal with that uncertainty. In this study, we apply an LCC and MC-based analytical model to a case study. Several retrofit scenarios are defined to improve the poor energy performance of a public housing building. The less investment-intensive alternative enable to achieve a 27% energy saving in comparison to the building as is, while the more investment-intensive alternative allows reducing consumptions by about two-thirds. We find that the scenarios characterized by lower upfront costs are more likely to show lower LCCs, regardless of the energy price. The novelty of this study lies in the fact that we show the prominence of the discount rate, which is a remarkable source of additional uncertainty. We find that the discount rate affects the results four times as much as the energy price; therefore, its estimation is critical to the soundness of thermo-economic evaluations.

Stochastic rail life cycle cost maintenance modelling using Monte Carlo simulation

The need for decision support systems to guide maintenance and renewal decisions for infrastructure is growing due to tighter budget requirements and the concurrent need to satisfy reliability, availability and safety requirements. The rail of the railway track is one of the most important components of the entire track structure and can significantly influence maintenance costs throughout the life cycle of the track. Estimation of life cycle cost is a popular decision support system. A calculated life cycle cost has inherent uncertainty associated with the reliability of the input data used in such a model. A stochastic life cycle cost model was developed for the rail of the railway track incorporating imperfect inspections. The model was implemented using Monte Carlo simulation in order to allow quantification of the associated uncertainty within the life cycle cost calculated. For a given set of conditions, an optimal renewal tonnage exists at which the rail should be renewed in order to minimise the mean life cycle cost. The optimal renewal tonnage and minimum attainable mean life cycle cost are dependent on the length of inspection interval, weld type used for maintenance as well as the cost of maintenance and inspection activities. It was found that the distribution of life cycle cost for a fixed renewal tonnage followed a log-normal probability distribution. The standard deviation of this distribution can be used as a metric to quantify uncertainty. Uncertainty increases with an increase in the length of inspection interval for a fixed rail renewal tonnage. With all other conditions fixed, it was found that the uncertainty in life cycle cost increases with an increase in the rail renewal tonnage. The relative contribution of uncertainty of the planned and unplanned maintenance costs towards the uncertainty in total life cycle cost was found to be dependent on the length of inspection interval.

Assessing the potential cost savings of introducing the maintenance option of ‘Economic Tyre Turning’ in Great Britain railway wheelsets

This paper assesses the potential cost savings of introducing a maintenance option known as ‘Economic Tyre Turning’ (ETT) in railway wheelset maintenance in Great Britain. It first develops a life-cycle cost model and puts forward a Monte Carlo simulation procedure to assess the life-cycle costs of different maintenance strategies, including ETT. This Monte Carlo simulation procedure samples from statistical degradation models that estimate the evolution of wear and damage trajectories of different wheelsets, and the maintenance impact of wheel turning in the loss of diameter in a more realistic manner by controlling random effects related to unit, vehicle and month of measurement. The main findings suggest that ETT may provide potential savings of around 0.8% up to 4.4% when compared to a simple wheelset renewal strategy, and between 2.0% and 4.7% cost savings when ETT is used in association with more complex strategies.

Life Cycle Cost Analysis for BESS Optimal Sizing

The increase of renewable energy sources (RES) installations all over the world during the past decades leads to a more sustainable energy scenario, however some drawbacks still persists and hinder the complete replacement of traditional fossil fuels. One of the main challenging issue is related to the intermittent production that generates serious problem in the power grids operations. Battery energy storage systems (BESS) represent one of the most promising technology which can help to overcome this issue, revolutionizing the way in which electrical power grids are designed and operate. The main aspects of these devices are related to the grid energy management, increasing the host capacity of RES, the system reliability and the users’ self-consumption. However, even energy storage systems present several pitfalls. They should be correctly maintained over the lifetime and they cannot be completely recycled at the end of their life, in addition, maintenance, decommissioning and disposal costs represent a significant share of the total cost. So as to consider these aspects in a holistic model the present work proposes a life cycle cost (LCC) model, which take into account all the most relevant cost components during the entire operation of the system.

Development of an Nearly Zero Emission Building (nZEB) Life Cycle Cost Assessment Tool for Fast Decision Making in the Early Design Phase

An economic feasibility optimization method for the life cycle cost (LCC) has been developed to apply energy saving techniques in the early design stages of a building. The method was developed using default data (e.g., operation schedules), energy consumption prediction equations and cost prediction equations utilizing design variables considered in the early design phase. With certain equations developed, an LCC model was constructed using the computational program MATLAB, to create an automated optimization process. To verify the results from the newly developed assessment tool, a case study on an office building was performed to outline the results of the designer’s proposed model and the cost optimal model.

Life Cycle Cost Methodology for Mixers based on MTTF Life Cycle Cost Model

Life Cycle Cost Methodology for Mixers based on MTTF Life Cycle Cost Model