Whole-life Cost Research Articles

Effect of separation pretreatment on environmental and economic performance of sludge resource utilization

As a new technology for accurate utilization of sludge resources, sludge inorganic–organic matter separation (IOMS) has attracted wide attention. This study examined the impact of this pretreatment on environmental and economic performance of sludge composting and incineration using life cycle assessment (LCA) and whole life costing (WLC). LCA results indicated that IOMS pretreatment reduced the energy conservation and emission reduction (ECER) values of composting and incineration by 56 % and 76 %, respectively. Meanwhile, WLC exhibited that IOMS pretreatment could cut the break-even year of incineration from 11 years to 4 years. The combination of organic sludge incineration/composting with inorganic sludge sintering ceramsite reveals excellent environmental and economic performance. The application optimization hypothesis analysis of these two routes in various provinces of China indicates that Jiangsu has the greatest development potential and should become a major promotion region.

Whole Life Costing Awareness and Implementation Challenges in the Sri Lankan Construction Industry

Construction industry is highly demanding, especially with regard to the project cost as a significant aspect. However, more informed cost advice can be produced considering the project’s life cycle that begins with the conception and ends with its disposal instead of using a conventional initial capital cost basis. Thus, Whole Life Costing (WLC) and Life Cycle Costing (LCC) concepts are essential. Though many LCC research studies exist, WLC studies are minimal in the Sri Lankan construction industry context. Therefore, this study aims to explore WLC awareness and implementation challenges in the Sri Lankan construction industry. A literature review was conducted to search for the concepts. Empirical data were gathered using questionnaires by implementing a quantitative survey strategy. Findings depict that the awareness of WLC in the Sri Lankan construction industry is poor, preventing its benefits. Moreover, this research identified difficulty in identifying includes and excludes for calculating WLC, lack of details at early stages, lack of awareness of WLC benefits, lack of understanding of WLC tools, lack of reliable data and lack of expertise/knowledge on WLC as the primary challenges in implementing WLC in the Sri Lankan construction industry. Therefore, these challenges must be mitigated for the beneficial WLC implementation in the Sri Lankan construction industry while enhancing awareness and knowledge of the WLC concept among professionals, especially quantity surveyors, to facilitate responsible initiation of WLC practices in the Sri Lankan construction industry. KEYWORDS: Awareness, Benefits, Challenges, Construction industry, Life Cycle Costing, Sri Lanka, Whole Life Costing

Interrelations of the Factors Influencing the Whole-Life Cost Estimation of Buildings: A Systematic Literature Review

The global GDP has witnessed a significant upswing, majorly due to the growth of the construction industry. Embracing the whole-life costing (WLC) approach, the construction sector strategically manages expenses across a construction project’s life cycle. However, despite its widespread adoption, accurate cost forecasting remains a major challenge. The intricate interplay of various influencing factors has not been fully explored, leading to inaccurate cost estimations. A comprehensive understanding of specific factors and their interrelationships is crucial to address this issue. Therefore, it is imperative to conduct further research to identify and explore the subtle nuances of these factors that impact whole-life cost estimation. Our study fills this gap, analysing 51 factors from 84 papers across prominent repositories. We assess interrelationships using a systematic literature review and pairwise comparison as in the analytical hierarchy process. The International Construction Measurement Standards (ICMS) framework structures these relationships and is represented in the causal loop diagrams (CLDs). The pioneering CLDs are a notable contribution, illustrating interrelationships and polarities among the 51 WLC factors. Six reinforcing loops and one balancing loop provide valuable insights into their dynamic nature. Importantly, lower-level factors do not always directly connect with upper-level factors. Instead, they interact within the same level before linking to top-level factors. These findings are significant for professionals, such as cost estimators, quantity surveyors and scholars, offering a comprehensive understanding of the WLC system.

Economics of geotechnical asset deterioration, maintenance and renewal

Transport and other infrastructure systems are supported on, adjacent to and retained by extensive systems of earthworks of varying (and increasing) age, and of variable original construction quality. These earthworks are subject to natural deterioration, which can be accelerated and complicated by the effects of climate change. The ACHILLES research program is providing improved understanding of earthworks behavior, performance and deterioration. It is also developing methods and tools to analyze and provide decision support for the construction, maintenance and renewal of earthworks, with particular emphasis on the management of existing, deteriorating assets. The work described here aims to identify the most cost-effective timing and means of extending earthworks asset lives and maintaining their safety and serviceability. Conventional cost-benefit analysis methods, of the type used for new infrastructure projects, do not directly provide the decision support needed for the maintenance and renewal of existing earthworks assets. An alternative approach is proposed and applied to a modeled example, demonstrating the potential asset management benefits of early, pre-emptive intervention, the economic attraction of deferred intervention, and the means of identifying an intermediate whole-life cost ‘sweet spot’, based on a timely assessment of intervention options. The handling of the uncertainty associated with earthworks behavior, deterioration rates and times to failure is also considered, as is the extension of the single-asset approach to the management of multiple earthworks assets.

Selected issues of the ecobalance analysis of recycled materials used in road construction

The paper presents road project issues in terms of environmental and cost analyses. Comprehensive assessment of the environmental and economic performance of engineering structures is based on quantitative environmental and economic information and draws on the results of life cycle assessment, life cycle cost and whole-life cost (WLC) analyses. The paper highlights the issue of the potential environmental impact of materials used in road construction, including those derived from the recycling process, in the context of life cycle assessment (LCA). The paper also outlines the requirements of a circular economy for the management of such materials. Attention was drawn to LCA as an important tool for obtaining comprehensive information on the environmental impact of the materials under study. Another element addressed in the paper is the topic of assessing the cost-effectiveness of road infrastructure. Attention was given to the total cost concept and the principle of cost interdependence. The problem of costs and benefits of road projects is described using the LCCA as an example.

Through-life stochastic carbon emission assessment and optimisation for critical assets

International governments and businesses are increasingly pledging more action to address human-induced climate change, including committing to the Paris Climate Agreement, which seeks to reduce global Greenhouse Gas Emissions (GHGE). Critical assets provide essential capabilities where failure could have catastrophic consequences. These assets have long service lives and are exposed to varying operational conditions and service requirements, which makes assessing through-life GHGE challenging. Current modelling techniques provide deterministic, single-point results, which provides a limited assessment of critical asset through-life GHGE where uncertainty can be significant. Furthermore, no modelling technique was identified that relates asset GHGE to Whole Life Cost (WLC) and operational effectiveness, which are both organisational priorities. This leaves decision-makers without robust information regarding the possible impacts of GHGE reduction strategies on the WLC and the operational effectiveness of their critical assets. This study develops a methodology framework to model critical asset GHGE with WLC and operational availability based on industry best practices and transferrable modelling techniques from other sectors. A model was created based on an in-service helicopter platform and was subjected to four test scenarios to demonstrate effects on WLC, GHGE and operational availability relative to baseline. Monte Carlo simulation was used to appropriately present modelling uncertainty.

A wholelife cost and carbon perspective of alternatives to septic tanks utilising nature-based solutions

Abstract Septic tank systems (STSs) are widely utilised flowsheets for decentralised wastewater treatment in the UK. With a growing consensus that STSs have a sizeable detrimental impact on the environment, there is a need for rural flowsheets with improved treatment capabilities. This study examines the lifetime cost and carbon emissions of using an enhanced septic tank nature-based solution (EST-NBS) to improve STS compared to a package treatment system (submerged aerated filter (SAF)). The wholelife cost (WLC) of the flowsheets and Scope 2 cradle-to-grave lifetime carbon emissions (LCEs) of the flowsheets were assessed. The EST-NBS flowsheets represent a lower cost improved treatment system than SAFs at population equivalents (PEs) from 5 to 1,000. An STS averages an LCE of over 4,000 kg CO2eq PE−1, with all other considered flowsheets having lower emissions. The EST-NBS flowsheets had lower carbon emissions than SAFs. Even at low populations upgrading from an STS to an EST-NBS is a competitive abatement strategy, with costs of £260 tCO2eq−1 emissions avoided, at 1,000 PE an NBS flowsheet has an abatement cost of –£17 tCO2eq−1. This shows the potential of using NBS flowsheets in rural wastewater treatment providing both a carbon and cost incentive against traditional designs.

Techno-economic analysis of sidestream ammonia removal technologies: Biological options versus thermal stripping

Over the past twenty years, various commercial technologies have been deployed to remove ammonia (NH4–N) from anaerobic digestion (AD) liquors. In recent years many anaerobic digesters have been upgraded to include a pre-treatment, such as the thermal hydrolysis process (THP), to produce more biogas, increasing NH4–N concentrations in the liquors are costly to treat. This study provides a comparative techno-economic assessment of sidestream technologies to remove NH4–N from conventional AD and THP/AD dewatering liquors: a deammonification continuous stirred tank reactor (PNA), a nitrification/denitrification sequencing batch reactor (SBR) and thermal ammonia stripping process with an ammonia scrubber (STRIP). The SBR and PNA were based on full-scale data, whereas the STRIP was designed using a computational approach to achieve NH4–N removals of 90–95%. The PNA presented the lowest whole-life cost (WLC) over 40 years, with £7.7 M, while the STRIP had a WLC of £43.9 M. This study identified that THP dewatering liquors, and thus a higher ammonia load, can lead to a 1.5–3.0 times increase in operational expenditure with the PNA and the SBR. Furthermore, this study highlighted that deammonification is a capable and cost-effective nitrogen removal technology. Processes like the STRIP respond to current pressures faced by the water industry on ammonia recovery together with targets to reduce nitrous oxide emissions. Nevertheless, ammonia striping-based processes must further be demonstrated in WWTPs and WLC reduced to grant their wide implementation and replace existing technologies.

Exploring the synergies between Life Cycle cost / Whole Life Cost and Building Information Modeling: A Systematic Literature Review

Life Cycle Costing (LCC) is a cost estimating approach for project and asset planning and delivery that considers the direct and indirect costs incurred over the entire life cycle of an asset. This approach can be expanded to the concept of Whole Life Cost (WLC), which additionally considers externalities and benefits. WLC can demonstrate the financial impacts, both positive and negative, of a project on its environment, in other words it can show its complete value. Despite its potential, the approach is still perceived as complex because, among other things, access to data can be difficult and the approach is still not supported by a standardized methodology. Building Information Modeling (BIM) could be used to address these issues as both WLC and BIM are deemed complementary. BIM provides WLC with better data management, improved calculation accuracy and visualization of project impacts. In return, WLC improves project understanding, decision making and reinforces life cycle thinking. This paper aims to study the potential synergies between BIM and WLC through a systematic literature review. The identification of these synergies helped form a frame of reference to better understand the opportunities that this combination can offer. Future studies would be needed to explore the application of BIM and WLC at different project scales and identify the context in which the combination of BIM and WLC is the most beneficial.

A Metaheuristic-Based Micro-Grid Sizing Model with Integrated Arbitrage-Aware Multi-Day Battery Dispatching

Rule-based micro-grid dispatch strategies have received significant attention over the last two decades. However, a recent body of literature has conclusively shown the benefits of operational scheduling optimisation while optimally sizing micro-grids. This is commonly referred to as micro-grid design and dispatch co-optimisation (MGDCO). However, as far as can be ascertained, all the existing MGDCO models in the literature consider a 24-h-resolved day-ahead timeframe for the associated optimal energy scheduling processes. That is, intelligent, look-ahead energy dispatch strategies over multi-day timeframes are generally absent from the wider relevant literature. In response, this paper introduces a novel MGDCO modelling framework that integrates an arbitrage-aware linear programming-based multi-day energy dispatch strategy into the standard metaheuristic-based micro-grid investment planning processes. Importantly, the model effectively extends the mainstream energy scheduling optimisation timeframe in the micro-grid investment planning problems by producing optimal dispatch solutions that are aware of scenarios over three days. Based on the numeric simulation results obtained from a test-case micro-grid, the effectiveness of the proposed optimisation-based dispatch strategy in the micro-grid sizing processes is verified, while retaining the computational tractability. Specifically, comparing the proposed investment planning framework, which uses the formulated 72-h dispatch strategies, with the business-as-usual MGDCO methods has demonstrated that it can reduce the micro-grid’s whole-life cost by up to 8%. Much of the outperformance of the proposed method can be attributed to the effective use of the behind-the-meter Li-ion battery storage, which improves the overall system flexibility.

GCONV Chain: Optimizing the Whole-Life Cost in End-to-end CNN Acceleration

The acceleration of CNNs has gained increasing attention since their success in computer vision. Since the heterogeneous layers cannot be processed by accelerators proposed for convolution layers only, modern end-to-end CNN acceleration solutions either transform diverse computation into matrix/vector arithmetic, which loses data reuse opportunities in convolution, or introduce dedicated functional unit to each kind of layer, which results in underutilization and high update expenses. To enhance the whole-life cost efficiency, we need a solution that is efficient in processing CNN layers and has the generality to apply to all kinds of existing and emerging layers. To this end, we propose GCONV Chain, a method to convert the entire CNN computation into a chain of standard general convolutions (GCONV) that can be efficiently processed by existing CNN accelerators with low-overhead hardware support. This paper comprehensively analyzes the GCONV Chain model and proposes a full-stack implementation to support GCONV Chain. Our results on various CNNs demonstrate that GCONV Chain improves the performance and energy efficiency of existing CNN accelerators by an average of 3.4x and 3.2x respectively. Furthermore, we show that GCONV Chain provides low whole-life costs for CNN acceleration, including both developer efforts and total cost of ownership.

A review of developments in cathodic protection systems for reinforced concrete structures

Cathodic protection is a corrosion management strategy for deteriorating reinforced concrete structures or it can be used as preventative measure in situations where corrosion may be expected during the service life as a result of the environmental exposure conditions. The technology has advanced over time. There are now a number of different systems that can conveniently be considered in three categories, including impressed current cathodic protection (ICCP), hybrid cathodic protection (HCP), and galvanic cathodic protection (GCP). Asset owners need to choose which option to use possibly without understanding the different sustainability, environmental, health and safety, construction, technical, operational, and monitoring aspects. Generally, it is agreed among corrosion engineers that ICCP is the most powerful and robust solution for corrosion management in structures with widespread deterioration. HCP and GCP can also be viable options, even in the most aggressive environments with future maintenance intervention. The advantages and disadvantages of each system are discussed in detail. This paper also explains why the commonly accepted life expectancy of ICCP systems is 50 to 75 years compared to HCP and GCP, which are typically limited to 15-30 years. The details of the likely maintenance requirements, associated timescales, and whole-life costs for a 100-year design life are analysed with references to sustainability. That includes a discussion about the corrosion management system that presents the lowest embodied carbon option for different environments.

Lean and Sustainable Construction: State of the Art and Future Directions

Only rapid and drastic reductions in greenhouse gases can prevent ever more widespread devastation and extreme weather events. Every increment in global heating is likely to compound the accelerating effects, according to the International Panel on Climate Change (IPCC), the world’s leading authority on climate science (IPCC, 2021). The aim of this special issue is to boost sustainable performance improvements in the construction sector, through raising discussions on advances and future directions of lean and sustainable construction theories and practices. The construction sector is known to be one of the largest environmental polluters, physical waste producers, and energy consumers throughout its lifecycle. The global construction market was forecast to grow by up to 70% between 2013 and 2025 (HM Government, 2013). The existing built environment is subject to growing global challenges, including decarbonising heating and cooling as well as the construction process, rapid population growth, anthropogenic climate changes and resource scarcity. The Covid-19 crisis further compounds these challenges by creating additional unprecedented social and economic pressures on the sector. This means that sustainability must become an integral part of our day-to-day practice, not an add-on. It is imperative that development, design, and construction professionals consider whole-life costs throughout the life of our built environment. There is significant evidence that integrating approaches to lean and sustainable construction can yield substantial benefits to the sector, and that the resulting synergy from combining the two approaches can fulfil the distinct objectives of each. The papers in this special issue are only a small beginning. Much more work is needed.

Design of adaptive structures through energy minimization: extension to tensegrity

This paper gives a new formulation to design adaptive structures through total energy optimization (TEO). This methodology enables the design of truss as well as tensegrity configurations that are equipped with linear actuators to counteract the effect of loading through active control. The design criterion is whole-life energy minimization which comprises an embodied part in the material and an operational part for structural adaptation during service. The embodied energy is minimized through simultaneous optimization of element sizing and actuator placement, which is formulated as a mixed-integer nonlinear programming problem. Optimization variables include element cross-sectional areas, actuator positions, element forces, and node displacements. For tensegrity configurations, the actuators are not only employed to counteract the effect of loading but also to apply appropriate prestress which is included in the optimization variables. Actuator commands during service are obtained through minimization of the operational energy that is required to control the state of the structure within required limits, which is formulated as a nonlinear programming problem. Embodied and operational energy minimization problems are nested within a univariate optimization process that minimizes the structure’s whole-life energy (embodied + operational). TEO has been applied to design a roof and a high-rise adaptive tensegrity structure. The adaptive tensegrity solutions are benchmarked with equivalent passive tensegrity as well as adaptive truss solutions, which are also designed through TEO. Results have shown that since cables can be kept in tension through active control, adaptive tensegrity structures require low prestress, which in turn reduces mass, embodied energy, and construction costs compared to passive tensegrity structures. However, while adaptive truss solutions achieve significant mass and energy savings compared to passive solutions, adaptive tensegrity solutions are not efficient configurations in whole-life energy cost terms. Since cable elements must be kept in tension, significant operational energy is required to maintain stable equilibrium for adaptation to loading. Generally, adaptive tensegrity solutions are not as efficient as their equivalent adaptive truss configurations in mass and energy cost terms.

Scenario-based life-cycle cost assessment to support sustainable investment in rural communal sanitation facilities: application to a school-based sanitation facility

Abstract Despite decades of investment in widening access to improved sanitation, much of the world still lacks access to functional sanitation facilities. Through much of the Global South, toilets are inoperable and often abandoned. Failure to understand and account for the whole-life cost of sanitation infrastructure, as well as the interplay between context-specific socio-economic determinants, is one explanation for this reduction in the service life of shared sanitation infrastructure. This issue is especially salient in school-based and communal facilities in middle- to low-income countries. Drawing on a case study of a sanitation facility in a government school in rural south India, we explore the relationship between user value, community-based capacity, and external support in determining the costs of operating and maintaining sanitation facilities over their lifetime. We develop a scenario-based life-cycle cost assessment methodology to examine the relational impact of these determinants on the ‘real’ cost of shared sanitation infrastructure. The analysis concludes that investment and interventions that stimulate demand and enhance the capacity of a community are the most cost-effective options for ensuring the sustainability of sanitation facilities in our case study site. We then reflect on the applicability and limitations of these findings for a wider range of communal sanitation facilities.

Comparative study of municipal solid waste incinerator fly ash reutilization in China: Environmental and economic performances

Harmless disposal and reutilization of municipal solid waste incinerator fly ash (IFA) attract growing interests due to the gap between increasing IFA generation and limited landfill space. Therefore, an economical-affordable and environmentally friendly approach to deal with IFA is required. Herein, major IFA reutilization technologies in China (IFA-to-cement, glassy slags, rock wool, and ceramsite) were evaluated and compared with the landfill using life cycle assessment (LCA) and environmental life-cycle costing (eLCC). Prior to assessments, material flow analysis (MFA) was used to establish a heavy metal transfer coefficient model. LCA results indicate IFA-to-cement and IFA-to-ceramsite outperform others while eLCC results show that IFA-to-ceramsite and IFA-to-rock wool are preferred, breaking even at years 3 and 5 compared to IFA-to-cement (new plant) at year 11. To reveal true costs of reutilization technologies, whole life costing (WLC) was applied to include externality costs via monetizing emissions. Major pollutants contributed to externality costs of these technologies were identified. IFA-to-ceramsite and IFA-to-rock wool technologies remain preferred with payback time as 4 and 6 years respectively. A scenario analysis suggests that replacing sintering aids with polluted soil and Sec-FA recovery could further improve the overall performance of IFA-to-ceramsite option. Policy scenario analysis reveals that corporate income tax and environmental protection tax have negligible impacts but waste disposal subsidy is vital for IFA reutilization technologies being economic feasible even without externalities.

Can Build-To-Rent Generate Affordable Housing Outcomes? A Whole-Life Costing Approach to Investment Analysis

Doubts remain among stakeholders in academia and the housing industry about the potential success of build-to-rent to generate positive outcomes for institutional investors and affordable dwellings for low- and moderate-income households. However, a systematic study on the viability of build-to-rent to deliver affordable housing in Australia is largely rare and non-existent in the literature. We fill this gap in the literature by investigating the financial viability of build-to-rent and its potential to generate affordable rental housing outcomes in Brisbane, Australia. Using rental prices from CoreLogic (Formerly RP data) and construction-related costing data from WT Partners Australia for 2019, we apply the whole-life costing approach to investment analysis and confirm that build-to-rent can be feasible in Australia under equity financing. Also, we find that under the current regulatory regimes and market structure, build-to-rent will fail to deliver affordable housing outcomes. Moreover, providing free land alone cannot help to make build-to-rent affordable. Thus, significant public subsidy and tax concessions, particularly on Goods and Services Tax (GST) on construction-related costs, may be required if build-to-rent developments are to generate affordable housing outcomes in Australia.

ACCOUNTABILITY IN PUBLIC PROCUREMENT: THE CASE OF FEDERAL PUBLIC ORGANIZATIONS OF ETHIOPIA

Public procurement is the main tool through which governments acquire goods, works, and services in the course of achieving public objectives. The study has focused on the accountability aspects of government procurement. The study has addressed the accountability in government procurement of the federal organizations of Ethiopia, and particular emphasis was given to ministries, agencies and commissions. Procurement accountability is related to being answerable to what has been planned, what has been implemented, what result has been achieved, and how the decisions have been made. Thus, the basic objective of the study is to examine procurement related accountability in selects federal organizations of Ethiopia. The research questions have been designed to examine how accountability related factors influence government procurement, and what areas are needed to be considered in promoting accountability. Accordingly, the data show that accountability in control of efficiency and effectiveness, ensuring value for money by taking the whole-life cost of acquisition is not strong enough in selection and awarding of suppliers, and professionalism and experiences are not created well to establish a strong accountability. It has been suggested that federal organizations have to revisit the accountability issues to obtain equivalent benefit from the amount they spend. Moreover, creating accountability to the successes as well as to failures will enhance answerability of individuals working in procurement related areas.

A transferable method for estimating the economic impacts of track interventions: Application to ground-borne noise reduction measures for whole sections of route

The environmental impacts of noise and vibration are becoming increasingly important in the assessment of new and upgraded railway routes. Vibration from railways propagates through the ground to nearby buildings where it may cause annoyance as feelable vibration or as re-radiated noise. To tackle the adverse effects of ground-borne noise a range of possible interventions are available, including softer rail pads, under-sleeper pads and under-ballast mats. The installation costs of such interventions are generally higher for the higher-performing track types. Additionally, there are potential effects on track maintenance costs which may be positive or negative, for example by reducing sleeper damage or increasing the need for ballast tamping. This study presents a socio-economic analysis of the effects of several interventions to reduce ground-borne noise. By selecting a whole route, the installation and whole-life costs are assessed using Network Rail’s Vehicle-Track Interaction Strategic Model (VTISM) and these are offset against benefits in terms of reduced social costs. Ground-borne noise is predicted at various distances from the alignment using the Modelling of Train Induced Vibration (MOTIV) model and the effect of track interventions is determined as insertion loss spectra. The re-radiated noise within a typical domestic building is then estimated using generic building transfer functions. Geographic Information System tools are used to estimate the population affected by ground-borne noise and their expected level of exposure. The methodology is illustrated using a case study route between Brighton and Portsmouth in the South of England.

Community Resilience-Oriented Optimal Micro-Grid Capacity Expansion Planning: The Case of Totarabank Eco-Village, New Zealand

In the grid-tied micro-grid context, energy resilience can be defined as the time period that a local energy system can supply the critical loads during an unplanned upstream grid outage. While the role of renewable-based micro-grids in enhancing communities’ energy resilience is well-appreciated, the academic literature on the techno-economic optimisation of community-scale micro-grids lacks a quantitative decision support analysis concerning the inclusion of a minimum resilience constraint in the optimisation process. Utilising a specifically-developed, time-based resilience capacity characterisation method to quantify the sustainability of micro-grids in the face of different levels of extended grid power outages, this paper facilitates stakeholder decision-making on the trade-off between the whole-life cost of a community micro-grid system and its degree of resilience. Furthermore, this paper focuses on energy infrastructure expansion planning, aiming to analyse the importance of micro-grid reinforcement to meet new sources of electricity demand—particularly, transport electrification—in addition to the business-as-usual demand growth. Using quantitative case study evidence from the Totarabank Subdivision in New Zealand, the paper concludes that at the current feed-in-tariff rate (NZ$0.08/kWh), the life cycle profitability of resilience-oriented community micro-grid capacity reinforcement is guaranteed within a New Zealand context, though constrained by capital requirements.