The ready-mixed concrete industry has gained significance due to the growing global need for mass housing, high-rise buildings, and infrastructure projects. Ready-mixed concrete must be used within two hours of production, necessitating local manufacturing. Turkey stands out as the third-largest producer of ready-mixed concrete globally, after China and the U.S. A better understanding of supply management systems in ready-mixed concrete companies is critical for enhancing operational efficiency, meeting the dynamic demands of clients, and achieving long-term stability and growth in such a competitive market. The main aim of this study is to evaluate ready-mixed concrete companies' supply management systems, focusing on three key aspects: (1) sales, (2) supply, and (3) waste management. A questionnaire was designed and randomly distributed to professionals employed by 150 ready-mixed concrete companies, achieving a 47% response rate with 70 returns. The findings indicate that the established practices among producers include frequent adjustments in unit pricing, offers of flexibility in payments, and the frequent use of discounts. Notably, half of the companies surveyed demonstrated high manufacturing capacity and high-quality production, with 75% supporting R&D operations. A significant portion (65%) employed over 15 technical professionals, and 64% utilized advanced vehicle tracking systems. Challenges in the availability of raw materials were common, and most companies employed waste management systems. These insights help to understand ready-mixed concrete production and distribution better and pave the way for optimizing supply chain dynamics in the ready-mixed concrete industry, offering pathways to improved efficiency and profitability.
A discussion about movies used to monitor activities on a construction site is presented. A new concept in time-lapse photography is introduced, where the user records pictures of a construction site shot at an optimal frame rate and is able to playback time-lapse movies at lower frame rates, this way adjusting the running time and detail of the playback movie. A software package is built in the Windows visual environment, capable of generating a time-lapse movie of a desired frame rate from a regular digital movie shot at the construction site. The selection of the most appropriate frame rate to handle different managerial issues such as analyzing claims, investigating accidents, and monitoring progress is discussed. Solutions are sought to the problem of storing the vast amount of digital information generated by movies, using commercially available storage devices.
This paper compares the performance of three different decision-tree-based methods of assigning attribute weights to be used in a case-based reasoning (CBR) prediction model. The generation of the attribute weights is performed by considering the presence, absence, and the positions of the attributes in the decision tree. This process and the development of the CBR simulation model are described in the paper. The model was tested by using data pertaining to the early design parameters and unit cost of the structural system of residential building projects. The CBR results indicate that the attribute weights generated by taking into account the information gain of all the attributes performed better than the attribute weights generated by considering only the appearance of attributes in the tree. The study is of benefit primarily to researchers, as it compares the impact of attribute weights generated by three different methods and, hence, highlights the fact that the prediction rate of models such as CBR largely depends on the data associated with the parameters used in the model.
The construction industry is one of the most male dominated industries around the world, not only when it comes to workers, but also as regards managers. Only 5% of the managers in the Swedish construction industry are women. The managerial competencies of individuals working as managers in the Swedish construction industry are researched to get a clearer understanding of the situation, and to investigate if this lack of balance between male and female managers has to do with differences in managerial competence. The management development questionnaire provided by Human Resource Development Press was sent to 143 managers in the Swedish construction industry and 112 respondents (44 women and 68 men) assessed themselves in 20 competencies, resulting in a response rate of 78%. The Mann-Whitney U test showed that female and male managers possess equal managerial competencies in 17 of the 20 competencies. Male managers rated themselves as having better managerial competency than females in two of the 20 competencies, namely ‘resilience’ and ‘decision making’. Female managers rated themselves as having better managerial competency than males in ‘sensitivity’, which follows the social norm of what is expected of a woman. It was also found that both groups scored high in decision making, reflecting traditional virtues of construction managers as decisive and active. The most important result is not the differences but the many similarities between women and men working as managers in the construction industry. Thus, it is concluded that female managers are as competent as male managers in the Swedish construction industry.
Paul Watson and Tim Howarth, Spon Press, London, 2011 321pp., ISBN 978 0 415 56911 8, £29.99 (pb) The first chapter of this book starts out with a comprehensive discussion of the various definition...
Fall-related accidents have received more attention in building construction than in civil construction as fall-from-heights is more common in building construction. In addition to social costs, construction companies face a significant financial burden when fall-related accidents occur. The major portion of the direct cost of accidents that involve falls includes the compensation paid by the employer to the worker. The employer and the worker try to reach an agreement on the size of the compensation, however, most of the time the process is contentious. The objective of this study is to predict the parties’ responsibilities for a fall-related accident by modeling the relationship between the employer and the worker using a multi-agent system. The research pursued a three-step method, including collection of data, development of a multi-agent model, and testing of the model. The model provides satisfactory results and can be used to quantify the employer’s and the worker’s responsibilities in construction fall accidents, hence avoiding any escalation to pursue arbitration or litigation.
This paper reports the findings of a study conducted by researchers at Illinois Institute of Technology under the direction and supervision of the ASCE Committee on Management Practices in Construction to investigate the expectations of the parties involved in the construction process, including designers, owners, general contractors, subcontractors, construction managers, and educators, relative to construction managers' duties. The findings suggest that while there is some consensus among parties to a construction project relative to CM duties particularly in the construction phase, there is also some disagreement, most of which appear to be between contractors and designers. Most disagreements are related to CM duties performed in the bidding and postconstruction phases of projects.
A Delphi process and a questionnaire survey are conducted to investigate the differences in the perceptions of entry-level professionals and long-time practitioners with regard to process quality in building projects. The factors that affect process quality in the three phases (design, construction, and operation) of a building project's life cycle are identified and ranked by the respondents' perceived degree of importance. The findings indicate that the perceptions of entry-level professionals and long-time practitioners are in agreement for most (74%) of the factors. Given the differences in the respondents' background, expectations, and experience, differences in perceptions are to be expected in the remaining 26% of the factors. Analyzing these differences helps in revising and improving existing training courses and academic programs. It is recommended that college programs include courses that treat the administrative aspects involved in the building project in great detail and that continuing education programs cover quality training and life cycle cost analysis.
This paper introduces an automated tool named Advanced Stochastic Schedule Simulation System (AS4). It integrates critical path method (CPM) schedule data exported from Primavera Project Planner (P3) and historical activity duration data obtained from a project data warehouse, computes the best-fit probability distribution functions (PDFs) of historical activity durations, assigns the PDFs identified to respective activities, computes the optimum number of simulation runs, simulates the schedule network for the optimum number of iteration runs, and estimates the best-fit PDF of project completion times (PCTs) without user intervention at any time. AS4 improves the reliability of simulation-based scheduling by effectively dealing with the uncertainties of the activities' durations, increases the usability of the schedule data obtained from commercial CPM software, and effectively handles the variability of the PCTs by finding the best-fit PDF of PCTs. AS4 encourages the use of simulation-based scheduling because it is simple to use and it simplifies the tedious and burdensome process involved in finding the PDFs of the many activities' durations, in assigning the PDFs to the many activities of a new network under modelling, and in estimating the best-fit PDF of PCTs.
The objective of the study reported in this paper is to compare contracts that include incentive/disincentive (I/D) provisions against contracts that do not include I/D provisions, with regard to the consequences of these measures. The study involves both completed and ongoing highway and bridge renovation/rehabilitation projects undertaken by the Illinois Department of Transportation (IDOT). After a general overview of I/D implementation, the results of a study that covered 28 I/D contracts (contracts that included I/D provisions) and 29 non-I/D contracts undertaken by IDOT during the five-year period 1989–93 are presented. The major finding of this study is that the majority of the I/D contracts are completed on time or sooner, which supports the use of I/D provisions in these contracts. However, this saving in contract duration seems to be accompanied by increased project costs most of the time.
The factors that affect process quality in the three phases (design, construction, and operation) of the life cycle of a building project are identified and ranked by degree of importance. The perceptions of long-time practitioners are obtained by means of a questionnaire survey. The findings indicate that management commitment to continuous quality improvement, management leadership in promoting high process quality, quality training of all personnel, efficient teamwork to promote quality issues at the corporate level, and effective cooperation between parties taking part in the project are generic factors that affect process quality. Industry-specific factors that are perceived by practitioners to enhance the quality of the building process include drawings and specifications that are consistent, designers and contractors that are selected on merit, communication practices between the parties that are effective, inspection of quality on the construction site that is diligent, a building operation manual that is thorough, and an adequate operation and maintenance budget that is planned as early as in the design phase.
In recent years, as Information Technology (IT) tools and Building Information Models (BIM) are adopted by more practitioners, it has become apparent that it is possible to have a faster and more efficient quantity take-off system. The efficiency of quantity take-off lies in the smart transfer of the information produced in the design process to construction. Existing BIM-based quantity take-off is performed in the design phase of a project. BIM-based systems provide a smart platform for information exchange between design and construction. A “model-based” system refers in this paper to a Building Construction Information Model (BCIM) coupled with a location-based scheduling process. BCIM offers an environment in the construction phase, where data are stored, updated, and reused via the evolving project libraries of a building contractor. BCIM is composed of three sub-models: (i) a building product model that provides the sections and quantities, (ii) a building resource and cost model that provides activity lists and labour consumptions to calculate activity durations, and (iii) a building process model that introduces the interdependencies of the activities. In the location-based scheduling process, a preliminary master schedule is obtained automatically from an information database, and then improved by the planner to fit the conditions of the company and of the project. The use of Advanced Line of Balance (ALoB) is proposed in location-based scheduling. The objective of this paper is to introduce the principles involved in quantity take-off in a “model-based” system as implemented by a contractor. The paper consists of three parts: (1) the “model-based” system (composed of BCIM and ALoB) is introduced as the theoretical background; (2) the steps in performing quantity take-off in “model-based” systems are described; and (3) Two residential construction projects are used to test the proposed quantity take-off principles.
The objective of the research presented in this paper is to explore the factors associated with company failures in the context of the construction industry. To that end, the four quadrants of an ‘environment/response’ matrix developed by Boyle & Desai (1991. Journal of Small Business Management , 29 , 33–42) are populated with Dun and Bradstreet's US business failure data for the construction industry. The study indicates that budgetary and macroeconomic issues represent 83% of the reasons for construction company failures. This implies that firms that take vigorous administrative measures to address budgeting issues and that react promptly to economic conditions by implementing appropriate strategic policies should be able to avoid failure. On the other hand, issues of adaptability to market conditions and business issues appear to have limited effects on company survivability (6% of the reasons for failure). This implies that administrative measures to fend off internal conflicts that originate for reasons beyond management's control and long‐term strategic decisions to regulate the firm's adaptation to market conditions can also help to prevent failure. An ‘input/output’ model appears to explain the business failure phenomenon better than the ‘environment/response’ one.
This paper proposes a radical change in industry practice that will improve the quality of the construction process and the levels of customer satisfaction derived from it by evaluating the quality performance of the contractor. An alternative theory is developed of what constitutes quality, client satisfaction, performance, and their interrelationships in the context of the construction industry. It should be noted here that the term construction client includes both the owner (i.e. the agency or organization funding the project) and the end-user of the construction (i.e. the general public). A comprehensive view of construction quality is proposed that deals with both the service (as received by the owner) and product (as received by the end-user) aspects of the construction project as well as the corporate quality culture. Such a dissection of construction activity facilitates developing strategies to define, operationalize, measure and improve construction quality. A frame4 work for the assessment of a contractor's quality performance is established. This involves gathering a list of contractor quality performance (CQP) indicators that are derived from various quality-related practices of the contractor at the corporate and project level. Finally, a contractor quality performance (CQP) evaluation model is introduced that can be used in a contractor prequalification and/or selection system. The CQP indicators are operationalized within the theoretical framework of the CQP evaluation model.
Public-Private Partnerships (PPPs) have gained significant importance in academia, government, and the construction industry over the last three decades. As a result, numerous studies have been published on the topic. These studies investigate various issues associated with PPP projects such as the length of the concession period, the selection of the private consortium, and the laws, rules and regulations that govern PPP implementation. However, there is a lack of systematic overview about issues with particular attention to financial aspects. This paper presents the outcome of a literature review that has been conducted to collect information about financial issues encountered in PPP implementation. This review included a total of 33 papers published in major journals and conference proceedings in the construction field in the last 25 years. At the end of the review, it was possible to identify a set of 19 financial issues that were grouped into five categories, namely (1) financing system, (2) financial market, (3) transaction costs and delays, (4) the public agency, and (5) the private consortium. The choice of focusing on this theme was prompted by the fact that the other issues (i.e., social, legal, and political) are all linked to financial issues. The identification of the salient issues related to financial aspects in PPPs is expected to contribute to the state-of-art in PPP research and implementation as it can pave the way to an empirical investigation that can in turn lead to a streamlining of the PPP processes throughout the world.
