The Effects of Buildability Factors on Rebar Fixing Labour Productivity of Beamless Slabs

 Buildability is an important factor affecting labour productivity. Nevertheless, a thorough search of the literature revealed a dearth of research into its effects on in situ reinforced concrete construction, especially at the activity levels. Since rebar fixing is an integral trade of this type of construction material, and beamless slabs are amongst the major encountered activities on construction sites, the objective of this research is to explore the buildability factors affecting its rebar fixing efficiency. To achieve this objective, a large volume of fixing productivity data was collected and analysed using the categorical interaction - regression method. As a result, the main and interaction effects of rebar diameter; reinforcement quantity; slab geometry; and reinforcement layer location are determined. The findings show a significant influence of these factors on the fixing operation, which can be used to provide designers and construction managers with feedback on how well the design of this activity considers the requirements of buildability, and the tangible consequences of designers‟ decisions on labour productivit

Buildability Factors That Influence Micro-level Formwork Labour Productivity Of Beams In Building Floors

Buildability is one of the most important factors that influence labour productivity. Nevertheless, a thorough literature examination revealed a dearth of research concerning the effects of buildability on labour productivity of in situ reinforced concrete construction. Beams are major components of building floors, and the objective of this investigation is to explore the buildability factors that influence their micro-level formwork labour productivity. Therefore, a large volume of productivity data was collected and analysed using a categorical interaction-regression method. As a result, the main and interaction effects of beam repetition, size, intersections and span geometry were determined. The obtained results indicate that the investigated factors significantly influence the forming operation labour efficiency and substantiate the importance of applying design rationalisation, standardisation and repetition concepts to the design stage of construction projects. The findings satisfy the explored activity buildability knowledge gap, which can be used to provide designers with feedback on how well their designs consider the buildability principle requirements, as well as their decision consequences on the forming operation productivity

The impacts of buildability factors on formwork labour productivity of columns

The impacts of buildability on formwork labour productivity of major in situ reinforced concrete elements such as, foundations, walls, columns, beams and slabs, are yet to be determined and quantified. The labour unit cost of columns formwork, in comparison with other constituents of the reinforced concrete frame, is constantly higher due to the forming complexity of these elements, especially non‐rectangular shapes, and the small output achieved in the operation. Therefore, the objective of this research is to investigate the impacts of buildability factors on columns formwork labour productivity. To achieve this objective, a large volume of productivity data was collected and analyzed using the categorical‐regression method. As a result, the impacts of the grid patterns, variability of column sizes, repetition, total and aver‐age shutter size, and geometry of columns are quantified. Apart from the variability of column sizes, the findings show significant effects of these factors on labour productivity, which can be used to provide designers feedback on how well their designs consider the requirements of buildability principles, and the consequences of their decisions on labour efficiency. Moreover, the depicted patterns of results may provide guidance to construction managers for effective activity planning and efficient labour utilization. Santrauka Statybos veiksniu itaka gelžbetoniniu konstrukciju, kaip antai pamatu, sienu, kolonu, siju ir perdangos plokščiu, klojiniu, irengimo darbo našumui turi būti nustatyta ir kiekybiškai ivertinta. Vienetines darbo sanaudos kolonos klojiniams irengti, palyginti su kitomis gelžbetoninio remo dalimis, yra didesnes, nes sudetinga suformuoti elementus, ypač kai kolonos yra ne stačiakampio formos. Todel šio tyrimo tikslas – nustatyti statybos veiksniu itaka kolonu klojiniu irengimui. Siekiant šio tikslo buvo surinkta daug duomenu apie darbo našuma ir šie duomenys buvo ištirti naudojant kategoriju‐regresijos metoda. Buvo ivertinti šie veiksniai: ašiu tinklas, kolonu dydžio ivairove, kartojimasis, bendrasis ir vidutinis užrakto dydis, geometrija. Neivertinus kolonu dydžio ivairoves, gauti rezultatai rodo didžiuli šiu veiksniu poveiki darbo našumui. Naudojantis šia informacija galima ivertinti, ar projektuotojas atsižvelge i statybos principus ir priimtu sprendimu itaka darbo našumui. Be to, rezultatai gal suteikti papildomos informacijos darbu vadovui, kaip efektyviau panaudoti darbo jega. First Published Online: 10 Feb 2011 Reikšminiai žodžiai: statybos veiksniai, kategorine regresija, kolonos, klojiniai, darbo našumas, racionalizavimas, kartojimas, standartizacij

Leadership that facilitates the successful implementation of Lean Six Sigma

Researchers have identified leadership as a critical success factor for Lean Six Sigma implementation. It is essential to understand leadership behaviours that facilitate the use of Lean Six Sigma. This paper aims to identify leadership styles from the literature that can facilitate Lean Six Sigma implementation, which in turn broaden the current understanding of the suitable leadership styles. Also, the authors aim to explore how leadership styles can enhance Lean Six Sigma operations. The authors systematically reviewed the literature on leadership styles and Lean Six Sigma. The results determined the leadership styles that can enable the use of Lean Six Sigma successfully. These leadership styles are as follows: situational (task-oriented or relation-oriented behaviour), transformational, servant, authentic, empowering, and distributed leadership. The authors provide a better understanding for practitioners and researchers from existing literature on how leaders' behaviours can enhance Lean Six Sigma implementation. It is not clear which style is the most dominant and effective. There is a lack in interpreting how these leadership styles linked to Lean Six Sigma implementation. There is a lack of empirical evidence most of the studies depended on a theoretical base. Very few studies have focused on leadership styles and Six Sigma success; to the best of the authors' knowledge only one paper has studied this. Also, there is scarcity in papers that addressed leadership styles that facilitate Lean Six Sigma implementation. This paper initiates a call to study Lean Six Sigma rather than focus only on either Lean or Six Sigma. This proposition guides future research based on the view that Lean management can share underlying assumptions with Lean Six Sigma characteristics. However, the mean limitation of this review is the use of specific keywords and database to identify studies

The Effects of Buildability Factors on Rebar Fixing Labour Productivity of Beamless Slabs

&nbsp;Buildability is an important factor affecting labour productivity. Nevertheless, a thorough search of the literature revealed a dearth of research into its effects on in situ reinforced concrete construction, especially at the activity levels. Since rebar fixing is an integral trade of this type of construction material, and beamless slabs are amongst the major encountered activities on construction sites, the objective of this research is to explore the buildability factors affecting its rebar fixing efficiency. To achieve this objective, a large volume of fixing productivity data was collected and analysed using the categorical interaction - regression method. As a result, the main and interaction effects of rebar diameter; reinforcement quantity; slab geometry; and reinforcement layer location are determined. The findings show a significant influence of these factors on the fixing operation, which can be used to provide designers and construction managers with feedback on how well the design of this activity considers the requirements of buildability, and the tangible consequences of designers‟ decisions on labour productivity </p

Motivational factors impacting the productivity of construction master craftsmen in Kuwait

In today's global economic conditions, improving the productivity of the construction industry is becoming more pressing than ever. Several factors impact the efficiency of construction operatives, but motivation is among the most important. Since low productivity is one of the significant challenges facing the construction industry in the State of Kuwait, the objective of this case study is to identify, explore, and rank the relative importance of the factors perceived to impact the motivational level of master craftsmen involved in primary construction trades. To achieve this objective, a structured questionnaire survey comprising 23 factors, which were shortlisted based on relevant previous research on motivation, the input of local industry experts, and numerous interviews with skilled operatives, was distributed to a large number of master craftsmen. Using the “Relative Importance Index” technique, the following prominent factors are identified: (1) payment delay; (2) rework; (3) lack of a financial incentive scheme; (4) the extent of change orders during execution; (5) incompetent supervisors; (6) delays in responding to Requests For Information (RFI); (7) overcrowding and operatives interface; (8) unrealistic scheduling and performance expectation; (9) shortage of materials on site; and (10) drawings quality level. The findings can be used to provide industry practitioners with guidance for focusing, acting upon, and controlling the critical factors influencing the performance of master craftsmen, hence, assist in achieving an efficient utilization of the workforce, and a reasonable level of competitiveness and cost effective operation

Causes of construction change orders in Qatar: Contractors' perspective

The construction industry involves complex processes which are prone to various changes and variations. However, it may be argued that the application of change orders within construction projects in the State of Qatar has become the rule rather than the exception. Therefore, the objective of this research is to identify, explore, and rank the relative importance of the preeminent causes instigating changes to construction contracts in the state. To achieve this objective, a structured questionnaire survey comprising 35 determinants, was distributed to a statistically representative sample of contractors. Using the relative importance index technique, the critical causes related to the client, consultant, contractor and exogenous groups are identified. The findings can provide industry practitioners and policy makers with guidance to mitigate, control, or effectively manage the primary causes of variations determined, which can further assist in meliorating the performance of the construction industry in a climate on the brink of witnessing an unprecedented boom in demand for expeditious delivery and restrained cost of constructed enterprises. 2016 Inderscience Enterprises Ltd.Scopu