Whole-life Cost Research Articles

The Application of Whole Life Costing in the UK Construction Industry: Benefits and Barriers

The application of whole life costing (WLC) technique is widely practised in other industries; however its use in the construction industry is marginal. The WLC approach encourages decision-making that takes account of the initial capital cost, running cost, maintenance cost, refurbishment requirements and disposal cost. The aim of this paper is to identify the key benefits and challenges relating to the application of WLC in the UK construction industry. This paper presents the results from 100 questionnaire survey sent to stakeholders in the construction industry including clients, contractors, quantity surveyors, project managers and engineers. The data analysis revealed that the most significant benefit to WLC is to optimise total cost of ownership while clients have been a significant challenge by not asking for WLC in their brief. The paper provides an insight and a better understanding of the major issues surrounding the application of WLC in the UK construction industry.

More for less through private finance highway maintenance

This paper shows how the private finance policy pursued by the UK government, applied to the delivery of highway maintenance services in Birmingham, provides a framework for the delivery of whole-life highways remediation, rehabilitation and maintenance needs at an affordable cost. Delivery of a best whole-life cost solution and the continual incentive to minimise expenditure results in a drive to optimise the use of physical and human resources, which in turn delivers environmental sustainability objectives. The £2·7 billion Birmingham highways maintenance and management service was also developed with local social and economic improvement in mind and this has shaped the interface with residents and engagement of the local supply chain in the delivery of the project.

Property-level stormwater drainage systems: integrated flow simulation and whole-life costs

Property-level stormwater drainage systems consist of roof drainage systems and those systems that connect buildings and their surrounding ground surfaces to main sewer networks, on-site rainwater harvesting or other capture systems. The design of these local systems has traditionally been based on simplistic approaches that fail to account for performance and integration. Given the extra demands associated with climate change, these limitations will take on increasing importance due to the potential for site-level flooding or water damage. To address the concerns, new tools are needed to describe and assess performance as well as to enable a more integrated approach. Research is presented on the development of an integrated property-level drainage simulation model and associated whole-life costing model. Application of the model illustrates the importance of accounting for flow interactions in order to assess the hydraulic effectiveness of different adaptation schemes. Similarly, the whole-life cost model can determine the through-life costs of adaptation strategies, hence enabling the assessment of the cost effectiveness of integrated designs. Les systèmes d'écoulement des eaux pluviales au niveau des biens immobiliers se composent de systèmes d'écoulement des eaux de toiture et de systèmes qui raccordent les bâtiments et leurs surfaces au sol environnantes aux réseaux d'égouts, aux systèmes de collecte des eaux pluviales sur place ou aux autres systèmes de récupération des eaux. La conception de ces systèmes locaux a été basée traditionnellement sur des approches simplistes qui sont incapables de rendre compte des performances et de l'intégration. Etant donné les exigences supplémentaires liées au changement climatique, ces limites prendront une importance croissante en raison des risques potentiels d'inondation ou de dégât des eaux au niveau du site. Pour répondre à ces préoccupations, de nouveaux outils sont nécessaires afin de décrire et d'évaluer les performances, ainsi que de permettre une approche plus intégrée. Il est présenté des recherches sur la mise au point d'un modèle intégré de simulation d'écoulement des eaux au niveau d'un bien immobilier et un modèle associé d'estimation du coût global du cycle de vie. L'application de ce modèle illustre l'importance de la prise en compte des interactions des flux afin d'évaluer l'efficacité hydraulique des différents programmes d'adaptation. De manière similaire, le modèle du coût global du cycle de vie est capable de déterminer le coût global des stratégies d'adaptation, permettant ainsi d'évaluer la rentabilité des conceptions intégrées. Mots clés: services du bâtiment, conception du système d'écoulement des eaux, systèmes d'écoulement des eaux, écoulement local des eaux, toitures, écoulement des eaux pluviales, coût global du cycle de vie

Whole Life Costing for Capability

Over recent years, there has been a large push towards developing techniques to facilitate Whole Life Cost (WLC) modelling, largely due to the increased interested in longer timescale projects and programmes, combined with the emergence of system-of-systems and network enabled capability concepts. This change in the implementation and management of large scale projects has necessitated the development of alternative methods of evaluating performance. This current work seeks to address the shortfalls in current costing methodologies when applied to these highly flexible environments, and to propose a conceptual model for dealing with the encountered complexities. The approach has a fundamental role and potential significance in the future of whole life costing for NEC but can also offer a potential paradigm shift in costing in traditional engineering environments.

Multi-criteria decision-making model for whole life costing design

Various decision-making tools have been reviewed. The interview surveys revealed that some typical bad decisions made in building designs may cause problems in building maintenance. Therefore, the importance of decision making involving multiple criteria during whole life costing (WLC) design is highlighted. Several methods have been assessed in interview surveys, aiming to solve WLC decision-making problems. During structured interview surveys, some methods are found unsuitable for decision making in WLC design process. The appropriate methods are selected at each stage of the decision-making process to develop an integrated fuzzy multi-criteria decision-making tool.

Life-cycle considerations in risk-informed decisions for design of civil infrastructures

Civil structures and infrastructures, such as buildings, bridges, and other facilities, are constructed and built for long service lives; many for over 50 or 100 years. In this light, the performance of an engineered system over its useful life span is naturally of major concern. The concern must include the assurance of a minimum level of reliability of performance, which will necessarily require inspections, repair, and maybe even retrofitting or replacement. The whole-life cost associated with this life-cycle performance, therefore, is the pertinent cost that ought to be the basis for determining the cost during the design stage (in terms of present value); this must include the maintenance and potential damage costs, besides the initial cost, over the life of a system. In this regard, significant technical and economic uncertainties can be expected and are unavoidable; therefore, decisions required in the design of such systems must consider risk associated with the probability of non-performance and serious damage or failure, as well as of the financial risk. The importance of these factors in the decision process at the design stage is emphasised and a practical approach for life-cycle consideration in formulating risk-informed decisions in the planning and design of infrastructure systems is described. The approach is illustrated with specific applications in the optimal design of civil infrastructure systems.

COST SAVINGS FROM PERFORMANCE‐BASED MAINTENANCE CONTRACTING

New procurement approaches combined with performance‐based building approaches should reduce costs, but empirical qualitative and quantitative studies are lacking. Performance‐based maintenance contracts give maintenance suppliers incentives to improve their way of working. Innovative, cost‐effective solutions that meet the performance criteria can be achieved, especially if the principle of whole‐life costing is being adopted. Indirect cost savings are expected as well. It enables maintenance contractors to assume responsibility for certain activities for which they are better equipped to perform than their clients. A calculation model was developed that calculates the net present value of the direct (product) and indirect (transaction) costs at project level for a competitive maintenance tendering approach and for performance‐based maintenance contracts. The findings show that performance‐based maintenance contracts reduce both direct and indirect costs compared to a competitive tendering approach. Essential preconditions are an early supplier involvement and longer term contracts, giving opportunities for maintenance product and maintenance process improvements. Santruka Nauji pirkimo būdai, derinami su subalansuotos statybos būdais, turetu mažinti išlaidas, tačiau trūksta empiriniu kokybiniu ir kiekybiniu tyrimu. Veiklos rezultatais pagristos priežiūros su tar tys skatina priežiūros paslaugas siūlančias bendroves tobulinti savo darbo būdus. Galimi no vatoriški, taupūs sprendimai, tenkinantys rezultatyvios veiklos kriterijus, ypač taikant viso naudojimo laiko išlaidu (angl. whole‐life costing) principa. Tikimasi sumažinti ir netiesiogines išlaidas. Priežiūra atliekantiems rangovams tai leidžia prisiimti atsakomybe už tam tikra veikla, kuriai vykdyti jie turi daugiau priemoniu nei ju klientai. Sukurtas skaičiavimo mo de lis, kuri taikant apskaičiuojama viso projekto tiesioginiu (produktas) ir netiesioginiu (sandoris) sa nau du dabartine grynoji verte (NPV), kai vykdomas priežiūros darbu pirkimo konkursas ir kai sudaromos veiklos rezultatais pagristos priežiūros sutartys. Rezultatai rodo, kad, lyginant su pirkimo konkursais, veiklos rezultatais pagristos priežiūros sutartys mažina ir tiesiogines, ir netiesiogines išlaidas. Būtinos salygos ‐ itraukti i priežiūros vykdyma tiekeja ankstyvuosiuose etapuose ir sutartis sudaryti ilgesniam terminui, suteikiant galimybiu tobulinti produkta ir priežiūros procesa.

Polymer composites in construction: a brief history

This paper discusses the development of advanced polymer composite material applications in civil and structural engineering over the past three decades. It illustrates the rapid growth in its utilisation in comparison with other construction materials, and the reasons for this. The material has extraordinary mechanical and important in-service properties, which when combined with other materials are utilised to improve stiffness, strength and durability and lower the whole-life cost and environmental impact. The paper demonstrates the types of structure that have been developed from the material, and the most advantageous way to employ composites in civil engineering. There is, however, generally a 20-year period from the fundamental innovation stage to the final use of the product by industry: this seems a very slow process. The paper concludes by summarising key successes of advanced polymer composites in construction.

Whole Life Performance Assessment: Critical Success Factors

Whole life costing (WLC) has become the best practice in construction procurement and it is likely to be a major issue in predicting whole life costs of a construction project accurately. However, different expectations from different organizations throughout a project's life and the lack of data, monitoring targets, and long-term interest for many key players are obstacles to be overcome if WLC is to be implemented. A questionnaire survey was undertaken to investigate a set of ten common factors and 188 individual factors. These were grouped into eight critical categories (project scope, time, cost, quality, contract/administration, human resource, risk, and health and safety) by project phase, as perceived by the clients, contractors and subcontractors in order to identify critical success factors for whole life performance assessment (WLPA). Using a relative importance index, the top ten critical factors for each category, from the perspective of project participants, were analyzed and ranked. Their agreement on those categories and factors were analyzed using Spearman's rank correlation. All participants identify “Type of Project” as the most common critical factor in the eight categories for WLPA. Using the relative index ranking technique and weighted average methods, it was found that the most critical individual factors in each category were: “clarity of contract” (scope); “fixed construction period” (time); “precise project budget estimate” (cost); “material quality” (quality); “mutual/trusting relationships” (contract/administration); “leadership/team management” (human resource); and “management of work safety on site” (health and safety). There was relatively a high agreement on these categories among all participants. Obviously, with 80 critical factors of WLPA, there is a stronger positive relationship between client and contactor rather than contractor and subcontractor, client and subcontractor. Putting these critical factors into a criteria matrix can facilitate an initial framework of WLPA in order to aid decision making in the public sector in South Korea for evaluation/selection process of a construction project at the bid stage.

Development of the Kirklees renewable energy toolkit, UK

In today's modern built environment, the introduction of renewable energy technologies as part of new builds or refurbishments is increasing. Although national building regulations are starting to drive this through legislation, some local authorities are pushing boundaries further and championing renewable energy projects within their districts. Kirklees Council in Huddersfield, UK, is one such authority. Its policy for sustainable buildings encourages renewable energy technologies to be incorporated in non-domestic new builds and refurbishment projects once energy efficiency and energy conservation measures have been incorporated into the design. The key for successful implementation of such policies relating to renewables lies with the building designers. Therefore, a user-friendly renewable energy toolkit has been created to assist engineers and architects in the successful implementation of renewable energy technologies and, in turn, Kirklees policy within non-domestic building projects. The renewable energy toolkit consists of seven elements including a whole-life costing and carbon dioxide saving calculation tool, guidance checklists and a case study library to encourage the sharing of experience and best practice. An overview of the results of the testing phase of the toolkit provides an insight into the development process of the resource; brief examples utilising actual project data indicate the potential success of such a tool.

Predicting the whole-life cost of a product at the conceptual design stage

This paper describes cost modelling research, industrial approaches and commercial systems and how these relate to whole-life cost estimating. The particular focus of the research described is the applicability of current approaches for the modelling of low-volume, infrequent products, such as complex electronic systems at the conceptual design stage. Traditional approaches, in particular those used to predict costs for mechanical systems, are described in detail, and the approach by which cost estimating relationships are ascertained is summarized. The approaches used within sectors such as aerospace, construction and injection moulding are discussed and evaluated. All of these are placed in the context of the design process, and in particular their relationship to the conceptual design of a product is described. Finally, a review of commercial systems and the methods they adopt and domains to which they are applicable are described. The use of these approaches in terms of whole-life cost of a product is then mapped.

A risk-based decision-support system for bridge management

Based on a study of those actively involved in bridge management this paper presents a novel framework for an advanced bridge management system. The framework has a modular format and includes components for dealing with inspection, data collection and storage, deterioration modelling, structural assessment, economic appraisal of maintenance, repair and rehabilitation (MR&R) actions through whole-life costing, work programme optimisation methodologies and a number of reporting facilities. Of primary importance to the bridge management process is the assessment of structural adequacy. If assessments are unduly conservative, structures will be unnecessarily restricted or strengthened, whereas if the rules are lax, some structures may be left in service without having an appropriate margin of safety against failure. To address this issue a procedure for a reliability-based assessment approach is presented and it is shown how such an approach, when part of the above system, can provide bridge managers with an innovative, rational, risk-based, decision-support tool.

Uncertainty in best value decision making

The sheer volume of decisions taken within the public sector procurement process prevents perfect and complete information being obtained and applied to every best value tender analysis that is carried out. As such, uncertainty must be accepted as a feature of the best value decision‐making process. This paper reports research which is developing a methodology for utilising the uncertainty component in best value tender analysis in order to create a more transparent decision making process. The main output of the research is the production of a robust support tool which aids the multi objective decision making process within the public sector of the UK construction industry by provoking rational discussion with respect to; the industry’s key performance indicators (KPIs), the client’s attitude to risk and provides a transparent audit trail of the decisions taken. The underlying rationale for the support tool is based on a combination of the Analytic Hierarchy Process (AHP), Multi‐Attribute Utility Theory (MAUT) and Whole Life Costing (WLC). The paper demonstrates the practical utility of the methodology of the tool through a tender decision process.

Corrosion monitoring of reinforcing steel in cement mortar by EIS and ENA

Health degradation by corrosion of steel in civil engineering, especially in rough environment, is a persistent problem. Environment pollution and global warming will exacerbate this problem. The assessment of whole-life costing and residual service life prediction of structures is very important. Pitting corrosion is the most important factor which influences the service life of the reinforced concrete structures in many chloride included environments. Electrochemical impedance spectroscopy (EIS) method is used to study the corrosion process of reinforcing steel in cement mortar. According to the results of the experiments, dispersion and diffusing effect control the electrochemical process of carbon steel corrosion in the cement mortar. By fitting the results with EC, the parameters about CPE and Warburg impedance are calculated. The pitting corrosion behavior of reinforcing steel in cement mortar has been studied by electrochemical noise analysis (ENA) method, the wavelet transform has been employed to analyze the EN data of reinforcing steel in mortar, and the energy distribution plot (EDP) is plotted. The experimental results show that the change of EDP during the corrosion process can qualitatively reveal useful information on corrosion mechanisms.

Fuzzy rule based system approach to assess cleaning costs of carpet flooring

The impact of ‘context of use’ to the whole life costs (WLC) of building elements has not yet been studied in previous researches. Lack of hard and detailed historical data constrained the use of traditional methods for this purpose. A fuzzy rule‐based system (FRBS) for any type of carpet cleaning cost estimate is one of a series of fuzzy models developed to estimate the WLC of building elements with the consideration of context of use to the elements. The fuzzy reasoning method, as the representation of human reasoning, is applied to WLC for the first time for carpet cleaning cost. The data used are the linguistic judgments from some experienced experts based on interview surveys. The implementation of the model is demonstrated in a case study. The result is assessed by the experts as an acceptable estimate.The paper concludes that Fuzzy Rule Based System is an appropriate method to model running costs of building elements. The model allows user to predict the cost variation of cleaning cost of carpet flooring according to its designed context of use.

Discussion: Decision-support tools for sustainable drainage

Virginia Stovin, University of Sheffield, UK I welcome this paper’s contribution to research aimed at identifying issues and opportunities associated with sustainable drainage system (SUDS) retrofitting. I believe that there are significant potential benefits associated with the broader application of SUDS retrofitting in urban environments, which are presently underexploited. Readers may also be interested in other ongoing research in this area. Swan attempted to address this complex problem through the development of a set of decisionsupport flowcharts. The work of Singh et al. in Glasgow is also relevant, and CIRIA C609 includes a number of simple decision-making tools. Atkins presented an excellent review of SUDS retrofitting issues and opportunities, including some useful insights into practical implementation issues. SNIFFER has also recently undertaken relevant research (Project UE3(05)UW5), and many of the forthcoming DEFRA ‘Making Space for Water’ pilot projects will consider issues and opportunities surrounding SUDS retrofit. The European Daywater project aims to provide SUDS decision-support tools and approaches, while a recent UKWIR/WERF project report provides a comprehensive USA/UK review of SUDS performance and whole-life costs.

Motorway noise barriers as solar power generators

During 2001 the Highways Agency (HA) commissioned TRL Limited to undertake a study to assess the feasibility of generating renewable energy on motorways and trunk roads. This study recommended that the HA undertake a full-scale trial of noise barriers incorporating solar panels. In 2004, two rows of solar barriers were installed in a cutting to the east of junction 9 of the M27. The trial was carefully monitored and showed that south-facing land alongside highways can successfully be used for solar barriers. In terms of maintenance, rainfall was effective in washing the panels; however, vegetation needs to be cut back at least annually unless the barrier is installed in a paved area. There was no evidence that drivers were distracted by the presence of the barriers or that noise reflected from the barriers would create any significant disturbance opposite the site. Although solar barriers are a feasible means of generating renewable energy on the highway estate, a whole-life cost analysis showed that the electricity generated over 30 years would not pay for the cost of installing the barriers unless the price of electricity was many times its current value.

Sustainable Development for Engineers – A Handbook and Resource Guide

It is crucial that engineers – from students to those already practising – have a deep understanding of the environmental threats facing the world, if they are to become part of the solution and not the problem. Is there a way to reconcile modern lifestyles with the compelling need for change? Could new improved technologies play a key role? If great leaps in the environmental efficiency of technologies are needed, can they be produced? Engineers are in a privileged and hugely influential position to innovate, design and build a sustainable future. But are they engaged or uninterested? Are they knowledgeable or ignorant? This book has been developed by a number of committed educators in European engineering departments under the leadership of Delft University of Technology and the Technical University of Catalunya to meet the perceived gap between what engineers know and what they should know in relation to sustainable development. The University of Delft decided as long ago as 1998 that all of its engineering graduates, working towards careers as designers, managers or researchers, should be prepared for the challenge of sustainable development and, as such, should leave university able to make sustainable development operational in their designs and daily practices. The huge amount of knowledge gathered on best-practice teaching for engineers is reflected in this book. The aim is to give engineering students a grounding in the challenge that sustainable development poses to the engineering profession, the contribution the engineer can make to attaining some of the societal and environmental goals of sustainability, and the barriers and pitfalls engineers will likely need to confront in their professional lives. Concise but comprehensive, the book examines the key tools, skills and techniques that can be used in engineering design and management to ensure that whole-life costs and impacts of engineering schemes are addressed at every stage of planning, implementation and disposal. The book also aims to demonstrate through real-life examples the tangible benefits that have already been achieved in many engineering projects, and to highlight how real improvements can be, and are being, made. Each chapter ends with a series of questions and exercises for the student to undertake. Sustainable Development for Engineers will be essential reading for all engineers and scientists concerned with sustainable development. In particular, it provides key reading and learning materials for undergraduate and postgraduate students reading environmental, chemical, civil or mechanical engineering, manufacturing and design, environmental science, green chemistry and environmental management.

Optimum design of sustainable concrete pavements

Optimum design of continuously reinforced concrete pavement (CRCP) can produce low-maintenance sustainable pavements with extremely long service lives. The advantages for roads and highways include low whole-life cost, economic and social benefits from reduced fuel consumption and pollution, reduced man-hour wastage, user frustration and aggravation. Unfortunately, the full potential of CRCP is not realised with conventional pavement design. Furthermore, very few successful structurally enhancing bonded concrete overlays (BCOs) at even lower whole-life cost have actually been achieved. This paper focuses on the essential requirements for a long-life sustainable pavement and outlines the essential shortcomings and deficiencies in conventional CRCP design. Optimum design can only be achieved if both a semi-rigid pavement model and a rigid pavement model are considered jointly. Furthermore, the abysmal failures of many BCOs can also be explained and rectified utilising various concepts outlined in this paper. Optimum combinations of fibre and bar reinforcement are also considered for even further advances in the future when more experimental data, especially field data, become available.

Innovations in concrete arch bridge design

Innovation in the design and construction of large-span arch bridges was investigated by considering buildability, maintainability and durability factors and their interaction at the design stage in terms of their effects on quality of construction and whole-life costs. In this study the utilisation of innovative composite arch ribs was examined and comparisons were made with concrete and steel arch ribs. A parametric study of a new composite arch rib was performed for a two-hinged arch in the span range 300–1000 m. The arch cross-section comprised three steel trusses interconnected by concrete slabs in composite action with the top and bottom truss chords. The results appeared promising for the span range 300–600 m in comparison with the steel arch and therefore the composite arch rib was tested in a new Croatian arch bridge carrying the highway over the Krka river. The fixed arch has a 204 m span and a rise of 52·0 m with a rise-to-span ratio of f/l=0·25.