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Loss of productivity is a contentious issue that has a profound impact on modern construction, yet existing literature provides no quantitative, data-driven method to compare the productivity of different construction projects or to assess their vulnerability to productivity loss. A new mathematically derived metric, called the "Risk of Productivity Loss (RPL)" score, provides such a method. RPL is a function of multiple distinct productivity factors. The RPL score is developed from a dataset of 166 electrical and mechanical projects, which collectively amount to 7.2 million labour hours. This large sample size makes the RPL score a reliable productivity benchmark for the electrical and mechanical construction industries due to their labour-intensive nature. The higher the RPL score, the higher the risk that a given project will suffer from productivity losses. To supplement the mathematical formula presented, objective data-based weights for multiple key productivity factors have been identified, reducing the subjectivity that affects many of the existing weighting assessment methods. RPL provides the industry with a single metric that allows tracking and assessment of productivity for multiple projects at a time so that a contractor may assess the successful reduction of productivity risk factors within the projects in their company. [ABSTRACT FROM AUTHOR]

Comparisons of industry sectors in advanced economies since the 1960s show that the construction sector has lagged in productivity growth rates, especially in the United States. Although the US and Canadian economies are highly integrated, Canada’s experience differs in key ways. Analysis of these differences offers insight into fundamental construction productivity drivers. Three levels of analyses of construction productivity in the US are provided in this study. The first analysis compared international levels of labour productivity growth. The second compared construction productivity between the US and Canada, and the third analysed cost estimating data from RS Means estimating manuals to measure the changes in labour and partial factor productivity in the US from 1995 to 2009. Statistical significance testing indicates that labour productivity remained nearly constant in the building sub-sector and that partial factor productivity has improved at an annual compound rate of 0.66%. This supports previous findings that US construction has stagnated but is still improving in Canada, with wage differentials and training systems as potential drivers of this difference. While growth rates of productivity seem to decline with higher absolute levels of productivity, there is no evidence that high absolute productivity levels preclude significant growth. [ABSTRACT FROM AUTHOR]

Productivity is a key driver for economic growth and prosperity in any country. The pursuit of productivity growth requires an understanding of the factors affecting productivity. The trend of productivity growth, along with the possible factors underlying such growth across Europe, the US and Japan, is thus examined. In particular, there is a focus on comparing the productivity performance of the construction sector to that of other industries. Using the recently released EU KLEMS1 database,2 a growth accounting framework was adopted to assess the contribution of the following factors to productivity growth (during 1971-2005): capital, labour quality and total factor productivity (TFP). It was found that there is a general slowdown in labour productivity growth in total industries including construction across major OECD countries, with the exception of the UK. The differences in labour productivity growth between construction and total industries can be largely explained by construction's poor TFP performance. With the exception of the UK, TFP negatively contributed to labour productivity growth in the period 1990-2005, suggesting that the industry has become less efficient in combining the factors of production. That phenomenon seems to be consistent across all selected countries and warrants further investigation. Indeed a better understanding of the factors underlying productivity growth in OECD countries is a prerequisite for effective intervention of policy makers to support sustained productivity growth. [ABSTRACT FROM AUTHOR]

With the development of a knowledge economy, it is reasonable to assume that the level of innovation should be particularly high and that it should have a major effect on investment and productivity across all sectors, including the construction industry. For a valid assessment of the economic performance of the construction sector in terms of its productivity, it is important that the economic benefits for the sector from technological change are properly recognized but the impact of such benefits may be 'hidden' due to measurement issues, as innovative activity and investment in intangible assets have both gone unrecognized in official statistics. Much of the innovation in the construction sector is hidden from conventional measures and, for the UK economy, there is evidence that investment in intangibles may be even greater than tangible investment, if a definition of intangible assets incorporating spending on a broad range of knowledge-based assets including organizational capital, human capital, etc. is taken. While accurate data are difficult to determine, an appraisal of the potential for utilizing existing data sources and for improved measurement is presented. [ABSTRACT FROM AUTHOR]

Poor productivity of construction workers is one of the major causes of cost overruns and schedule slippages in construction projects. Anecdotal evidence suggests that workers' attitudes towards higher productivity may not be limited to purely financial rewards, but inherently linked to many other latent factors. Some building construction projects in Melbourne are compared to each other to ascertain the factors that influence productivity. The factors and their relative importance impacting on workers' productivity are investigated by using a structured questionnaire survey approach. The survey was formulated with 72 questions covering three broad categories, namely (1) project planning; (2) incentives/disincentives; and (3) job satisfaction. Perceived best practices that impact on improvement of productivity on site were identified from 19 targeted experts. Analytical hierarchy process shows that the biggest influences on productivity are planning and programming. The outcome of this study should assist management decisions in determining the effect on productivity and suggest possible improvements to establish the appropriate management procedures for most productive use of labour resources in construction projects. [ABSTRACT FROM AUTHOR]

Current research focuses on assessing productivity, cost, and delays for concrete batch plant (CBP) operations using Artificial Neural Network (ANN) methodology. Data were collected to assess cycle time, delays, cost of delays, cost of delivery, productivity, and price/m 3 for the CBP. Two ANN models were designated to represent the CBP process considering many CBP variables. Input variables include delivery distance, concrete type, and truck mixer's load. Output variables include the assessment of cycle time, cost of delays, delivery cost, productivity, and price/m 3 . The ANN outputs have been validated to show the ANN's robustness in assessing the CBP output variables. The average validity percent for the ANN outputs is 96.25%. A Time‐Quantity (TQ) chart is developed to assess the time required for both truck mixers and the CBP to produce a specified quantity of concrete. Charts have been developed to predict cycle time/truck, delays/truck, cost of delays/truck, cost of delivery/m 3 , and price/m 3 . [ABSTRACT FROM AUTHOR]

The assessment process of productivity and cost of bored pile construction is dictated by unseen subsurface obstacles, lack of contractor experience and site planning. These problems complicate the estimator's role in evaluating pile equipment productivity and cost. Current research discusses the assessment of piling process productivity and cost using the deterministic technique. Data are collected through questionnaires, site interviews and telephone calls to experts in various construction companies. Many variables have been considered in the piling construction process, such as pile size, depth, pouring method, soil type and construction method. Five deterministic models have been designated to assess productivity, cycle time and cost. The developed models are validated whereas 79% of the outputs have been predicted with more than 75% accuracy. Consequently, three sets of charts have been developed to provide the decision-maker with a solid planning, scheduling and control tool for piling projects. If a pile has 60' depth with f-18 (18? diameter pile) in clay soil using a 5' auger height, the cycle time is estimated as 56 and 65.5 minutes; however, productivity is 6 and 5 holes/day for dry and wet methods, respectively. [ABSTRACT FROM AUTHOR]

Previous research suggests that the construction industry is characterized by (1) particular complexity factors owing to industry specific uncertainties and interdependences, and (2) inefficiency of operations. The aim of this study was to analyse the operations and behaviour of firms as a means of dealing with complexity. The observations made indicate that the industry as a whole is featured as a loosely coupled system. Taking this as a starting point, the couplings among activities, resources and actors were analysed in different dimensions. The pattern of couplings builds on two interdependent layers: fight couplings in individual projects and loose couplings based on collective adaptations in the permanent network. It is concluded that the pattern of couplings seems to favour short term productivity while hampering innovation and learning. [ABSTRACT FROM AUTHOR]

Discrepancies exist between aggregate and activity productivity measurements in the US construction industry. Multiple studies using aggregate industry measures suggest that construction productivity has declined over the long term. A longstanding problem with the aggregate measures concerns the difficulty of controlling for inflation so as to accurately measure real output. As an alternative, average activity productivity, measured by individual work activities, indicates that construction productivity has increased over the same time period. Activity measurement data have been collected for 200 construction activities over a 22-year time period from commercial estimation manuals used by contractors and owners to estimate the cost and time requirements for construction. This paper examines the discrepancies between aggregate and activity measurements and suggests possible reasons for their existence. [ABSTRACT FROM AUTHOR]

This paper seeks to assess whether the implementation of formal quality schemes in the construction industry delivers higher productivity when measured at site level. The work reports an experiment in which the resources used by construction contractors to build housing association houses varied in accordance with the level of formal quality certification held by the contractors. It concludes that formally assured organizations use fewer resources to create the same output. [ABSTRACT FROM AUTHOR]

The ‘European construction industry’ is a fiction that tends to obscure its heterogeneous character and to mar studies and policies of the European Commission aimed at improving the internal and external ‘competitiveness’ of the sector. In order to assess the process of integration in Europe under the impact of its own dynamics as well as Union policies, this paper looks at the dynamics of the sector from three different aspects: as investment, production and labour process. It shows, in particular, the persistent regional and social disparities dividing the industry into separate entities. Political attention tends to focus on a small number of construction companies competing for a few projects which represent the European dimension. Yet, these companies still rely on their respective national bases and local labour from the place where construction is carried out. Persistent divisions between the states are also reflected in the low level of transnational organization of the construction industry. The policy of the European Commission generally ignores these divisions and attempts to establish principles intended to make a whole sector more ‘competitive’, while its component parts, operating at hugely different levels of productivity, do not even meet on the same market. This paper argues that, instead of trying in vain to introduce a ‘knock-out’ system of competition in the EU Member States, a targeted approach might help raise productivity in lagging regions and thus improve the basis of competitiveness on global markets. [ABSTRACT FROM AUTHOR]

In academic research, the traditional Box–Jenkins approach is widely acknowledged as a benchmark technique for univariate methods because of its structured modelling basis and acceptable forecasting performance. This study examines the versatility of this approach by applying it to analyse and forecast three distinct variables of the construction industry, namely, tender price, construction demand and productivity, based on case studies of Singapore. In order to assess the adequacy of the Box–Jenkins approach to construction industry forecasting, the models derived are evaluated on their predictive accuracy based on out-of-sample forecasts. Two measures of accuracy are adopted, the root mean-square-error (RMSE) and the mean absolute percentage error (MAPE). The conclusive findings of the study include: (1) the prediction RMSE of all three models is consistently smaller than the model’s standard error, implying the models’ good predictive performance; (2) the prediction MAPE of all three models consistently falls within the general acceptable limit of 10%; and (3) among the three models, the most accurate is the demand model which has the lowest MAPE, followed by the price model and the productivity model. [ABSTRACT FROM AUTHOR]

The just-in-time (JIT) philosophy has been used in the manufacturing industry for some forty to fifty years. This system increased not only the productivity of the industry but also the quality of its products. Explorative studies have been completed in recent years to see how JTT can be applied into the construction industry to reap the benefits of the system. Most of these studies have concluded that it is possible to apply the techniques of JIT in the construction industry with some modifications. Taking into consideration that one of the key components of site management is concerned with waste management (i.e. bringing wastage down to the minimum), this study focuses on applying JIT for site layout to improve productivity and quality. By eliminating waste on site, controlling the movement of inventory coming into the site and within the site, and controlling the usage of mechanized plant and equipment, smooth work flow can be achieved. [ABSTRACT FROM AUTHOR]

Compared with the manufacturing sectors the construction industry suffers from relatively lower productivity, although some attempts are being made to overcome low construction productivity by introducing manufacturing-based concepts to the construction industry. The just-in-time (JIT) concept is one of the manufacturing-based concepts introduced to streamline construction operations and help raise productivity in the industry. The fundamental philosophy of JIT is to eliminate wastes from delays, transportation, unnecessary processing and unnecessary motion. This is because any activities which do not add value to a process are considered wasteful. Construction productivity therefore can be enhanced if these activities are eliminated. This paper presents an accounting procedure for measuring JIT wastes. The case study of a private condominium project, where this accounting procedure was applied, shows that indeed JIT wastes can be identified and eliminated to raise construction productivity. [ABSTRACT FROM AUTHOR]

This paper explores the issues around the remarkable growth in labour-only subcontracting on a self-employment basis in the British construction industry over the last 30 years. Following a presentation of the available data from the Department of Employment, the paper explores the reasons behind this remarkable development, and concludes that the main reason for the growth of self-employment since 1977 is the strategic choice of construction companies to emphasize flexibility over productivity as sources of competitive advantage. The paper also explores the implications of this strategic choice, and concludes that, as a result, the ability of the industry to increase productivity and quality is compromised due to the ways in which labour-only subcontracting and self-employment hinder training and innovation. [ABSTRACT FROM AUTHOR]

Projects can be delayed for a large number of reasons. The third phase of an investigation into such factors focused on the causes of construction delays in Hong Kong. A questionnaire was based on 83 factors identified in previous phases of the investigation. Analysis of the responses reveals differences in perceptions of the relative significance of factors between clients, consultants and contractors. There was general agreement about the relative importance of delay factors such as unforeseen ground conditions. Improving productivity is a useful approach to controlling delays. Important factors affecting productivity itself are thus examined in more depth, with a view to enhancing productivity and reducing delays. The conclusions of this phase of the investigation include a ranking of factors and factor categories that are perceived by different groups of project participants to contribute to delays. For example, higher-ranking factors, such as unforeseen ground conditions, and factor categories such as project-related factors, are found to merit special management attention in countering construction delays. The high degree of disagreement as discerned between the groups of clients, consultants and contractors is indicative of their experiences, possible prejudices and lack of effective communication. It is also confirmed that productivity and other non-scope factors such as effective communications should supplement the project scope factors incorporated into the construction time prediction models that were proposed in the previous phases of this investigation. [ABSTRACT FROM AUTHOR]

Constructors confronted with the need to compress or accelerate a construction schedule face the potential for extreme difficulties. Unfortunately, a limited knowledge base exists for determining the techniques, methods, or concepts to be employed in mitigating these potential negative outcomes of lower labour productivity rates and higher project costs. This paper explores the impacts of planned and unplanned schedule compression on labour productivity. Additional impacts of schedule compression related to project costs and schedule duration are also evaluated. Telephone interviews and questionnaire surveys primarily were used as the means for data collection to determine which methods of schedule compression identified are most effective in each of the aforementioned areas. Members of the National Electrical Contractors Association (NECA) were used as the data source for this investigation because of their diversified experience and because of the support received from NECA management. A number of schedule compression methods are presented that have been shown to be effective. [ABSTRACT FROM AUTHOR]

Many variables have an impact upon construction time and cost overruns in Indonesia. A questionnaire survey was undertaken of project managers working on high-rise construction projects in two Indonesian cities: Jakarta and Yogyakarta. The variables identified were ranked according to their perceived importance and frequencies of occurrence. Inflationary increases in material cost, inaccurate material estimating and project complexity are the main causes of cost overruns. The predominant causes of delay are design changes, poor labour productivity and inadequate planning. Using factor analysis techniques, delay and cost overrun variables were grouped into factors, and their relationships analysed. Although Indonesia specific, the results reflect construction management problems common to developing countries. [ABSTRACT FROM AUTHOR]

A sectoral analysis of the construction industry in Indonesia indicates that it has grown considerably in recent years. Efforts are under way to adapt to this new situation, including exploring ways to increase productivity. A survey of top contractors indicates that certain functions including procurement practices, cost control, scheduling and management integration need much improvement. A survey of top design professionals indicates that they are concerned about design practices, computer utilization in planning and scheduling activities, and goal setting techniques. There seem to be conflicting opinions regarding the construction management project delivery system. Both, contractors and design professionals are willing to cooperate in any productivity enhancement programme but neither are willing to fund such activities. [ABSTRACT FROM AUTHOR]

Despite his acknowledged role in the execution of construction projects, the crew foreman's function has received little attention. The study described here tries to answer three questions: How does the foreman divide his workday time and on what subjects? With whom does he communicate? Can a correlation be detected between the way he divides his time and the performance of his crew? The research is based on a sample of 24 foremen in the USA and 32 in Israel. The findings throw more light on the perennial discussion to what extent the foreman is manager or supervisor, and whether one can replace replanning with preplanning. [ABSTRACT FROM AUTHOR]

Productivity rates are among the most essential data needed in the construction industry. The accuracy of productivity rates is crucial for the determination of direct relationships between these rates and subjects such as estimating, cost control, scheduling, and resource management, among others. Past experience in the construction industry has shown that great variation in production rate values for the same construction item is attributed to the effects of project conditions which are commonly called influence factors. This paper describes the development of a statistical model that illustrates the quantitative relationships between influence factors and the productivity rates. The application of such a model will enable the user to estimate productivity rates with a higher degree of accuracy in future projects. [ABSTRACT FROM AUTHOR]

Survey of production outputs, production problems and motivation of construction operatives on seven sites showed that there is scope for improving productivity in the Nigerian construction industry. A system for monitoring and improving construction productivity on sites is presented. The recommended system works on a pre-potent factor principle using a simple flow-chart of necessary actions. The paper also introduces the concept of hyper-production into construction productivity and advocates the development of a construction productivity expert system in developed countries where builders can afford computers. [ABSTRACT FROM AUTHOR]

The measurement of labour inputs to the productivity process is the major subject of this study. It is concerned with the simplification of the operation of collecting labour productivity information on site where it is not a one-time task and should be a continuous effort to acquire as many measurements as possible to ensure constant field management control of the project. The study employs the simple methods of work sampling and learning curves for field management control to measure labour utilization during the construction process.
Work sampling technique is a simple and easy technique to use in the management of site resources, time and labour, but it is only an indirect measurement of actual productivity. Therefore, the study has concentrated on demonstrating the correlation between the work sampling percentages, unit rate productivities, and the learning rates of global activities through the development of productivity projection models. Thus, it is possible to quantify productivity and learning rates directly through the simple technique of work sampling. [ABSTRACT FROM AUTHOR]

Productivity in the use of resource inputs is of critical importance to the construction industry. This paper is intended to discuss the relative merits of the most commonly used measures of productivity for the purpose of assessing the productive and allocative efficiency of construction in the 1980s. The paper concludes that the total factor productivity method is the ideal against which the other approaches should be judged. Roth average labour productivity and average capital productivity suffer from serious problems in assessing the efficiency of contracting operations. However, tinder certain circumstances, either can provide an adequate alternative measure. Of the two main single-factor measures of productivity, capital productivity appears to be superior in most aspects to average labour productivity as a means of assessing the overall financial management of a construction firm. Notwithstanding the problems associated in contracting activities and also the difficulties inherent in obtaining suitable data, capital productivity is recommended for most circumstances when total-factor productivity measures cannot be applied. [ABSTRACT FROM AUTHOR]

Bonus, payment-by-results, financial incentives (or any synonymous method for systematically encouraging productivity) has been the grumbling appendix to industrial relations in the building industry, with arguments for and against it's use, thoroughly rehearsed over some 70 years. Oddly, this polarization of belief, reminiscent of the Lilliputan warfare between Bigendians and Littlendians, is not carried over into other, generally mechanistic techniques for programming, resource allocation, et al., whose veracity and effectiveness are disinterestedly investigated. A case for defining a proper role for financial incentive schemes is argued, starting with an apparent contradiction; change in the workplace disrupts group cohesion and social structures, yet building operations, by their very nature, continuously alter both work environment and workplace groupings, without similarly affecting building workers. The examination proceeds by juxtaposing the well known Herzberg hygiene/motivation theory with the generally overlooked Davis (1948) investigation of building workers, then focuses upon monotony, briefly comparing ‘job-satisfaction’ and ‘no job-satisfaction’ experienced in other industries, moving to a conclusion via the findings of Borcheding and Oylesby (1974) that good site organization engenders high job-satisfaction and productivity. [ABSTRACT FROM AUTHOR]

Although much has been written about the rapid rate of construction in the USA compared with the UK, very little investigation has been undertaken to determine exactly how the rates of construction are achieved. This paper briefly describes the differences between the UK and US construction industries, and then uses a case study of a US construction project to examine the relationship between the design of an element and the construction on site. The US designer pays attention to the way the components will be assembled on site, being concerned with the overlap of work packages undertaken by specialty subcontractors. Because each of the work packages is clearly defined and isolated from other work packages, the contractor has better control over the rate of production on site. [ABSTRACT FROM AUTHOR]