The general contractor-subcontractor relationship has been a focus of interest in the literature and yet its impact on a general contractor's economic performance remains a virtually unexplored area in the construction management literature. This research presents the findings of a questionnaire survey administered to 500 large US general contractors to explore this issue. The findings reveal that maintaining a relationship of high quality with subcontractors is positively and strongly associated with the perceived performance of general contractors responding to the survey.
Observations in the industry and a recent survey indicate that construction companies are anxious to improve their marketing activities. Literature regarding industrial marketing of consumer products is quite abundant, but has limited use in the construction industry. On the other hand, most of the few published works regarding marketing in the construction industry concentrate on design services as opposed to construction services. This paper discusses marketing principles and practices that could be applied by construction contractors. It reports on an exploratory survey of marketing executives employed by the ENR top 400 contractors, carried out to identify the existing marketing practices and analyze them by size of company, type of work undertaken, type of contract used, and the proportion of new clients versus repeat clients. Results support the need for an in‐depth study for the development of feasible and efficient marketing strategies for construction contractors.
Contract administration is one of the most important pillars of a construction project.Its effect starts at bidding and lasts until the end of the guarantee period.A common mistake made by construction owners is structuring the construction contract in a way that minimizes the owner's risks by relaxing the timing of owner payments, including heavy penalty clauses, requesting bank guarantees with indefinite duration, etc.However, a well-balanced construction contract may protect the work against any unexpected events, avoid potential disputes between the parties, and provide contract clauses that are fair to both parties.Being one of the pioneers in this area, the aim of this study is to compare the time and payment-related clauses of the Turkish bespoken construction contracts with standard FIDIC contracts and provide important insights and guidelines to practitioners.In this study, 304 bespoken contracts undertaken in the Turkish building construction market are analyzed and compared against standard FIDIC conditions.The results show that the timing of the payments is similar to those in FIDIC general conditions, yet time extension is mostly awarded for force majeure only.The majority of the projects were delayed in most cases observed independently from the type of contract and wording of the time extension clause.Recommendations are made to structure a more balanced building construction contract and more successful construction project management in Turkey.
Branding secures easier financing, higher rates and occupancies and repeat business in the hospitality industry. Hotel operators use architectural and interior design elements to create uniquely differentiated products for their brands. Owing to the expected benefits, hotel owners often involve brand chain hotel operators in designing their properties. However, although they are heavily involved in the design, hotel operators leave it to the owner to deal with the construction of the property and with the challenge of accomplishing the design intent while completing the project on time and within budget. The teaming/timing sequences available for a prospective hotel owner are analysed. The consequences of the timing for adding the builder to the project team in different project delivery methods are identified. Also, the best practices relative to design coordination, constructability reviews, value engineering, mock-up room reviews, price confirmation, and project handover are considered. A custom software program ‘HotPlan’ is developed to assist owners in generating conflict-free sequences of teaming/timing options and evaluating the consequences of their preferences. Comparisons of the HotPlan-generated sequences allow users to pick the alternative that most agrees with their intentions. The study is relevant to other types of projects such as residential and office buildings, airports, and hospitals where the operator of the facility may participate in the development process right from the start.
iTake-Over: The Recording Industry in the Digital Era sheds light on the way large corporations appropriate new technologies related to recording and distribution of audio material to maintain their market dominance in a capitalist system. All too commonly, scholars have asserted too confidently, how the rise and reign of digital music has diminished the power of major record labels. In iTake-Over, music scholar David Arditi argues otherwise, adopting a broader perspective by examining how the recording industry has strengthened copyright laws for their corporate ends at the expense of the broader public good, which has traditionally depended on the safe harbor of fair use. Arditi also challenges the dominant discourse over digital music distribution, which has largely adopted the position that the recording industry has a legitimate claim to profitability at the detriment of a shared culture.
Sound transmission through multilayered building elements was investigated in this experimental study in which sound transmission losses were measured in 28 wall samples with various layer configurations including gypsum board, steel plates, vinyl damping material, glasswool, and airgap. ASTM E90-90 standard was used in the experiment that was conducted at the Riverbank Acoustical Laboratories within a study supported by a grant from IIT/IITRI. The effects of some physical parameters were investigated and comparisons were made in terms of frequency-dependent TL, Rw, and STC values. Test specimens of two sizes (10 m2 and 2.9 m2), were used to derive a size-effect correction which could be used in comparison of measured data and those to be calculated for infinite elements. It was found that the sound insulation values for small-size elements were higher at low frequencies than those of large-size elements, whereas they were lower at mid and high frequencies for both single- and multilayered elements. Statistical analysis indicated that the difference was significant and more emphasized for double gypsum walls with airgaps. Based on the experimental data, variations of transmission loss nd insulation values according to gap width and layer configuration are presented in comparative charts and the results are discussed.
<p>The line-of-balance ~LOB! method of scheduling is well suited to projects that are composed of activities of a linear and repetitive nature. The objective of this study is to set down the basic principles that can be used in the development of a computerized LOB scheduling system that overcomes the problems associated with existing systems and creates solutions to problems encountered in the implementation of repetitive-unit construction. The challenges associated with LOB scheduling include developing an algorithm that handles project acceleration efficiently and accurately, recognizing time and space dependencies, calculating LOB quantities, dealing with resource and milestone constraints, incorporating the occasional nonlinear and discrete activities, defining a radically new concept of criticalness, including the effect of the learning curve, developing an optimal strategy to reduce project duration by increasing the rate of production of selected activities, performing cost optimization, and improving the visual presentation of LOB diagrams.</p>
As construction projects become more complex and challenging to execute, project managers need to develop work schedules that consider as many objectives as are critical to project success. A work schedule designed to optimize all these objectives is likely to enhance project performance. However, achieving a balance among these objectives is difficult because they frequently conflict with each other. Many optimization models have been developed over the years that can factor in different objectives. Although previous optimization studies have contributed to the body of knowledge by individually adding one or two objectives to the classical time–cost trade-off (TCT) problem, none of these studies simultaneously optimized more than three or four objectives at a time. Clearly, there is a need for a multiobjective optimization model to generate work schedules that increase the likelihood of achieving as many project objectives as necessary. This study was motivated by the need to fill this research gap. The objective of this study was to develop a mathematical multiobjective optimization model for the time–cost–quality–schedule flexibility-resource fluctuation trade-off problem in small-scale construction projects. The proposed model is novel because it (1) considers five important objectives of construction project scheduling at the same time, (2) quantifies all objectives to provide an accurate reflection of construction site conditions, and (3) objectively determines the optimal compromise solution using a distance-based method rather than subjectively from a set of Pareto-optimal solutions. The applicability of the proposed model is demonstrated with an illustrative example. The key results of this study are as follows: (1) the optimal solution obtained depends on the project manager's priorities relative to the objectives; and (2) in optimization problems with more than two objectives, considering the objectives one at a time may result in misleading solutions, because the effects of the other objectives are ignored in this optimization. Consequently, multiple objectives must be considered simultaneously rather than one at a time. The proposed model is expected to provide project managers with a work schedule that balances five or more objectives, increasing the chances of successful project performance.
This study compares certification systems for green healthcare facilities implemented worldwide. Healthcare facilities are complex structures designed to provide uninterrupted service while involving substantial resources, high energy consumption, and heavy human and material traffic. The COVID-19 pandemic emphasized the importance of designs that ensure hygiene, reduce environmental impact, and improve energy efficiency, making green certification systems for healthcare facilities increasingly critical. Eight certification systems currently in use across eight countries were examined, four from advanced economies (LEED in the U.S., BREEAM in the U.K., Green Star in Australia, and CASBEE in Japan) and four from developing economies (YeS-TR in Turkiye, IGBC in India, GBI in Malaysia, and GREENSHIP in Indonesia). Country selection considered regional diversity, similarities in environmental policies, and the potential for healthcare infrastructure development. A literature-based comparative analysis was conducted, and seven key categories were identified for evaluating sustainability: sustainable land and transport, water and waste management, energy efficiency, material and life cycle impact, indoor environmental quality, project management process, and innovation. The comparison revealed considerable overlap among the systems but also highlighted shortcomings in addressing healthcare-specific needs. This paper contributes to the advancement of sustainability assessment in the healthcare sector by highlighting the need for certification schemes specifically designed for medical facilities. The findings emphasize the necessity of developing healthcare-tailored frameworks that not only address environmental performance but also capture the unique operational, functional, and clinical dynamics of this sector.
Degisen sosyal, ekonomik ve kulturel etmenler, gayrimenkul olarak konut alim karar tercihlerini etkilemektedir. Konut alicilarinin ulke, bolge ve yorelerin dinamiklerine gore degiskenlik gosteren tercihleri, konut projelerinin ozelliklerini ve akimlarini dogrudan etkilemektedir. Ekonomik durum ve yikici depremler, son on yilda Istanbul’daki konut proje gelistirme yaklasimlarini ve alici kararlarini yeniden sekillendirmistir. Degisik mimari ozelliklere, sosyal tesislere sahip, cesitli tasarim ve uygulama niteliklerini karsilayan projeler ilgi gormekte ve tercih edilmektedir. Bu calismada, yerlesmek uzere alim gerceklestiren potansiyel konut alicilarinin tercih olcutlerinin tespit edilmesi ve siralanmasi amaclanmistir. Cozumleme calismasi, Istanbul’daki konut projelerinin cogunluguna imza atan buyuk konut uretim firmalarinin bakis acisindan gerceklestirilmistir. Bu amacla, gerek yazin taramasi, gerekse de bolgede uygulama yapan profesyonellerle yapilan gorusmelerde elde edilen bilgilere Analitik Hiyerarsi Yontemi (AHY) uygulanmis, konut uretim firmalarinin bakis acisindan konut alicilarinin tercihleri dokuz kategoride ele alinmistir. Calismalar sonucu, bu etkenlerin, firmalarin satis ve pazarlama politikalari, fiyat seviyesi ve odeme kosullari, sosyal etkenler, mimari ozellikler, konum ve ulasim gibi ozellikler sebebiyle firmadan firmaya cesitlilik gosterdigi saptanmistir. Bolge ozellikleri ve gerceklerinin yapilan analitik calismayla degerlendirmesi ve hem konut alicilarina, hem de konut ureticilerine yansitilmasi bu calismanin temel amacidir.
Abstract: Project acceleration often results in claims. A LISP program for performing time impact analysis for project acceleration is presented. The program helps the user identify the number of days by which the project can be accelerated and what the user's share will be of the acceleration costs involved. The program analyzes the as‐planned, as‐built, and utility data files submitted by the user and identifies all delayed, accelerated, added, and canceled (DAAC) activities. It then generates as‐planned, as‐built, projected, adjusted, owner‐accountable, and contractor‐accountable schedules. The program performs a compression analysis on the remaining portion of the project. After a consultation session with the user, it apportions acceleration costs between the owner and the contractor in an equitable way. This program is expected to help settle claims.
Purpose Planning for increased contractor profits should start at the time the contract is signed because low profits and lack of profitability are the primary causes of contractor failure. The purpose of this paper is to propose an integrated profit maximization model (IPMM) that aims for maximum expected profit by using time-cost tradeoff analysis, adjusted start times of activities, minimized financing cost and minimized extension of work schedule beyond the contract duration. This kind of integrated approach was never researched in the past. Design/methodology/approach IPMM is programmed into an automated system using MATLAB 2016a. It generates an optimal work schedule that leads to maximum profit by means of time-cost tradeoff analysis considering different activity acceleration/deceleration methods and adjusting the start/finish times of activities. While doing so, IPMM minimizes the contractor’s financing cost by considering combinations of different financing alternatives such as short-term loans, long-term loans and lines of credit. IPMM also considers the impact of extending the project duration on project profit. Findings IPMM is tested for different project durations, for the optimality of the solutions, differing activity start/finish times and project financing alternatives. In all cases, contractors can achieve maximum profit by using IPMM. Research limitations/implications IPMM considers a deterministic project schedule, whereas stochastic time-cost tradeoff analysis can improve its performance. Resource allocation and resource leveling are not considered in IPMM, but can be incorporated into the model in future research. Finally, the long computational time is a challenge that needs to be overcome in future research. Practical implications IPMM is likely to increase profits and improve the chances of contractors to survive and grow compared to their competitors. The practical value of IPMM is that any contractor can and should use IPMM since all the data required to run IPMM is available to the contractor at the time the contract is signed. The contractor who provides information about network logic, schedule data, cost data, contractual terms, and available financing alternatives and their APRs can use an automated IPMM that adjusts activity start times and durations, minimizes financing cost, eliminates or minimizes time extensions, minimizes total cost and maximizes expected profit. Originality/value Unlike any prior study that looks into contractors’ profits by considering the impact of only one or two factors at a time, this study presents an IPMM that considers all major factors that affect profits, namely, time-cost tradeoff analysis, adjusted start times of activities, minimized financing cost and minimized extension of work schedule beyond the contract duration.
Reasonably accurate cost estimation of the structural system is quite desirable at the early stages of the design process of a construction project. However, the numerous interactions among the many cost-variables make the prediction difficult. Artificial neural networks (ANN) and case-based reasoning (CBR) are reported to overcome this difficulty. This paper presents a comparison of CBR and ANN augmented by genetic algorithms (GA) conducted by using spreadsheet simulations. GA was used to determine the optimum weights for the ANN and CBR models. The cost data of twenty-nine actual cases of residential building projects were used as an example application. Two different sets of cases were randomly selected from the data set for training and testing purposes. Prediction rates of 84% in the GA/CBR study and 89% in the GA/ANN study were obtained. The advantages and disadvantages of the two approaches are discussed in the light of the experiments and the findings. It appears that GA/ANN is a more suitable model for this example of cost estimation where the prediction of numerical values is required and only a limited number of cases exist. The integration of GA into CBR and ANN in a spreadsheet format is likely to improve the prediction rates.
Hazard recognition skills are a critical factor in construction safety. Eye-tracking technology is considered the direct and objective way to study hazard recognition issues. The paper aims to evaluate the effect of daily safety training on people's hazard recognition skills using eye-tracking technology. The study focuses on three aspects: (1) effect of safety backgrounds (safety certifications, construction-related education, and construction-related work experience) on people's hazard recognition performance; (2) impact of daily safety training on hazard recognition skills and on the scan path of workers with varying backgrounds; and (3) comparison of the impact of daily safety training on the scan path of people with different hazard recognition levels. An eye-tracking experiment was conducted to obtain participants' eye movement data and achieve the study's objectives. The results of the study indicate that people who are educated in a related field of study demonstrate an advanced level of hazard recognition abilities, while safety certificates and construction-related work experience do not appear to have a significant impact. Following daily safety training, the participants exhibited more careful examination of construction scenarios. Additionally, individuals with higher hazard recognition levels displayed increased confidence in their hazard recognition judgments. This study makes a significant contribution to the existing body of knowledge by demonstrating the potential of eye-tracking technology to investigate the effect of safety training on visual scan paths. The results of this study emphasize the importance of considering various safety training methods for workers with varying hazard recognition levels to enhance their performance in identifying hazards.
Construction litigation expenditures have increased considerably over the years. An universal prediction model (UPM) was developed to predict the outcome of construction litigation and, hence, encourage settlements out of court. The study was conducted by using 151 Illinois circuit court cases filed in the period 1987–2005. UPM consists of data consolidation, attribute selection, hybrid classification, and performance assessment. A code was written to automate the entire process in the Waikato environment for knowledge analysis. UPM is versatile and scalable. The findings resulted in a higher prediction rate than those obtained in previous studies. The system proved to be quite robust and fast. If the outcome of construction litigation can be predicted with reasonable accuracy and reliability, all parties involved in the construction process could save considerable money and time.
Many state agencies are shifting towards nighttime construction/maintenance especially on urban highways. While nighttime construction/maintenance has many advantages, it also has disadvantages compared to daytime construction. One major disadvantage is that nighttime construction operations may be more hazardous to both drivers and construction personnel because of visibility problems at night. Visibility depends on providing more luminance contrast to the driver than otherwise available. A system called LUMINA was developed to measure the luminance of six commonly used safety vests in nighttime construction/maintenance work areas. LUMINA was used (1) to perform field experiments that involved recording on videotape the performance of the safety vests; and (2) to convert the video movies into snapshots, to calculate the average luminance of the vests tested, and to index them. These tests were conducted not in a laboratory setting but on actual construction/maintenance sites that involved different lighting, traffic, and weather conditions. Two of the six safety vests outperformed the others significantly. © ASCE.
