An Overview Of A Constructions Productivity Construction Essay

An Overview Of A twistings Productivity anatomical structure EssayRecently, social structure productiveness is on a long- limit slide and it is recognized as pains challenge. System, people, materials, information and energy must f slump impressively and efficiently to produce its objective at luxuriously productivity to bring about eddy at lowest possible toll with possible shortest prison termframe (Picard, 2005).Productivity is critically important in reflection industry. Many researchers discombobulate expressed their vex over productivity in braid industry. Defining productivity is not a simple task to everybody. Different people give give different definition and understanding. Most of them agreed that marketable output was essentially the main measure employmentd.Increased productivity was a leading concern to all Committee stakeholders such as users, contractors, and aspect dig unions and led by the owner. The crook users emphasized the enquire of collect ing info reckonly applicable to productivity cash advance. The Committee was concluded that the front-line construction foreman/supervisor would be a reliable source of information. These informants would be asked to provide their judgment of the greatest impediments to a productive construction learn (Tucker, 2003).Definition of productivityWithin these several decades, many researchers attain defined the productivity term in their studies in a number of ways. The term productivity has different meanings to different people. Many individuals automatically think lone(prenominal) of lug unions when the term productivity is mentioned. Others associate capital expenditures with the term. for each one of these interpretations is only partly correct (Adrian, 1993). Many researchers scram attempted to define precisely the meaning of productivity and below atomic number 18 most of it that referred from their studiesOglesby et al. (1989), presented that productivity washstand b e defined as in-place value divided by inputs . Some researchers have defined it as whole kit-hours divided by the equivalent quantity of work. In construction, productivity normally potty be understood as work quantity divided by man-hours (or work-hours) consumed to accomplish the work.Productivity = Work QuantityMan-hours gibe to Dolman, Parham, Zheng, (2007), productivity is a measure in order to know how much output is produced per unit of input.Diewert Lawrence, (2006) presented that productivity can be defined as the take of sparing output per unit of input and overly per worker. Productivity is important to the wealth and well-being of a nation and give efforts to improve productivity egest at all take aims of society.According to Hwang and Liu, (2005), productivity is an effective index that can indicate output of construction work quantity versus the input of resources. Productivity of a crew is directly impacts the cost and time needed to complete a task. By ana lyzing and forecasting productivity, project make outr can be more than effective to control and predict project time and cost throughout execution up to completion.Thomas and Mathew, (1986) presented that no standardized productivity definition had been established in the construction industry. It is difficult to define a standard productivity measure because companies use their own systems which are not standardized. Association simply illustrates the productivity amid an output and an input. The form has been widely used and existing in literature over the years in construction industry is Productivity = Input/ railroad sidingProkopenko, (1987), defined the productivity as effective and efficient utilization of all resources, dig up, visualizet and materials.According to Jugdev, et al.,(2001), productivity is a ratio between inputs and outputs. In figure the productivity, it is important to specify the inputs and outputs that to be measured because there are many inputs suc h as labors, materials, equipments, tools, capital and design in construction system.Uusi-Rauva and Hannula, (1996), presented that productivity can be defined as internal capacity of the organization or other object to be measured. A more precise definition of productivity is the following output divide by the input that is used to generate output. Output is consists of products or services and input is consists of materials, labor, capital, energy, etc. Productivity is not only affected by the quantities of inputs and outputs but also the qualities of inputs and outputs.According to Halligan, et al., (1994), there are many ways to define productivity. In construction, it is usually taken to mean labor productivity which is units of work placed or produced per man-hour.Teicholz, (2004), verbalise that productivity in construction industry was measured by constant contract dollars of new construction work per hourly work hourThe Bureau of ram Statistics (BLS, 2009) of the U.S. De partment of Labor was defines productivity into two type which are labor productivity and multi actor productivity. Labor productivity can be measures as output per hour of labor and it is used in over 40 industries including construction. Productivity can be metrical by dividing the quantity of work completed (Quantity) by number of labor hours used to complete the work (Man Hours). A productivity value represents performance of an cognitive border with respect to time and cost, where activity duration and activity cost is directly affected by productivity.Duration (Hours) = Quantity of works(Quantity / Man Hours)= Quantity of WorksProductivityThe formula above indicates how critical the reliability of the productivity factors in estimation time.Measurement of productivityThere is controversy surrounding productivity that root in the differences in data collection. It is due to incorrect in assuming productivity measured uniformly and that all published productivity values have the same basis (Whiteside, 2006)Overall conception of productivity is difficult to express or to measure. It is sometimes expressed either in terms of output from labor or from services or from capital invested. These parts of expressions often do not give an accurate picture of the overall position. Although, there are measurements of some or all of the inputs and outputs of the industry but they still failed to combine these measurements into any satisfactory measure of efficiency. In fact, the ratio is easy to compute if the unit uses a single input to produce a single output (Choy, 2008).According to Whiteside, (2006), production is average direct labor hours to install a unit material. He also stressed that in perfect realness, perfect productivity (1.0) will be accomplished in 40-hour work week, with everyone taking all of their holiold age and vacation days planned. It is regarding to all the engineering drawings must be 100% complete, there would be no delays of any kind, everyone would work safely, everything would fit perfectly at the first time, the live on would be 70 degrees Fahrenheit and there would be no litigation at the end of the project. But, we do not live in perfect world and true productivity is often poorly understood. The first challenge in understanding productivity is lacking of common terms. The definition of hours identified as direct labor should be consistent. Second is too much focus in determining productivity which is incorrectly placed on the individual worker. Productivity is something to do with the worker because many workers work at the same rates. The main thing should be focused in productivity measurement is proper or complete planning. It is because like-out-sequence work will contribute to lower productivity due to the rework hours required to complete the original task. The final challenge is how to make productivity similarity when the data used in productivity studies before have the same basis. Productivity i s not based on wage rates or cost data alone and it is improper to combine wage rate, hours and material quantities to make productivity comparison.According to Hwang and Liu, (2009), construction productivity studies have centered on the acknowledgement of factors that influence productivity and quantification of the impact of such factor on productivity. As a result, there were versatile qualitative and quantitative factors have been discovered and various methods for productivity have been presented. Majority of those methods are based on relationships between productivity and factors. Based on Thomas and Yiakoumis (1987), they stated that theory underlying the factor instance is the work of crew is affected by a number of factors. If the cumulative effect of these disturbances can be mathematically represented, then the expected material productivity can be estimate. But, it is not always feasible to quantify the impact of various factors and represent the relationships math ematically. Another limitation is the value of many cogitate factors in future is not available and thus, they have to be estimated. In fact, some of the factors can be correlated with others which the correlation whitethorn be high or lower under different situations.There is several research efforts have been devoted to developing models. The models that being used in the construction industry are such as belowAccording to Sonmez and Rowings, (1998) Portas and AbouRizk, (1997), recommended Neutral Network (NN) techniques which have been used to develop method of productivity prediction.Everett and Farghal, (1994), recommended learning curves that for various activities.Abdelhamid and Everett, (1999), have applied time series analysis to evaluate hoisting performance comparing the CRANIUM technology with the conventional technique.According to Brockwell and Davis, (2002), ARMA (autoregressive moving average) models are used to model time-lagged relationship of self-correlated obs ervations within a single series.Cumulative Average and Simple Moving Average that wisely used to model a single time seriesExponential Smoothing produce forecasts of weighted value of past observation with exponentially decreasing weights (NIST, 2006).Although there are numbers of publications exist on construction productivity, there is no agreed upon definition of work activities nor a standard productivity measurement system. Most of researchers have concluded that it is difficult to obtain a standard method to measure construction labor productivity because of project complexity and unique characteristics of the construction projects (Oglesby et al. 1989). The uniqueness and non repetitive of operation in construction projects make it is difficult to develop a standard productivity definition and measure (Sweis, 2000).Current measurement of productivity in construction industryOur labor productivity experts specialize in labor productivity analysis and may utilize the followin g industry-recognized methodologies, where appropriateMeasured Mile AnalysisWork try outComparable Work StudyGeneral and Specialty Industry Studies (Mechanical Contractors Association of America MCAA,Construction Industry Institute CII, Business Roundtable, etc.)Total Cost methodModified Total Cost MethodTime and Motion StudiesThe selection of a particular productivity analysis methodology is depends on the project facts, the character of the events being analyzed, the nature and extent of available labor data and may vary from project to project. Each of the above-referenced productivity analysis methodologies has inherent its own advantages and disadvantages. port Consulting has extensive experience handling construction labor productivity claims and construction claims consultants are skilled at tailoring productivity analysis approach to subject a projects needs and constraints (ICII, 2009).Factors influence productivity in constructionAccording to Tucker, (2003), he presente d the most factors that can affect the construction productivity especially on situate as belowDesign specifications, drawings, documents have to be improvedField support for timely responses have architect/engineer on site with field competencyCoordinate Design/ReviewTimely RFIs/RFPs (Request For Informations/Request For Proposals)Construction/Project management competencyHe also suggested that productivity improvement should be done based on this areaConstructability of the design documents with input of major(ip) contractors on schedulequality and realismCoordination among major contractorsPre-project planning communication and teamwork between owners, design professionals, contractors and laborImprovement of the construction management process.Parisi, (2008) presented that potential factors influence the construction productivity are many, including out-of-sequence work skilled labor shortages worker crowding/congested work areas interference of trades owner interference design problems and defects contractors inadequate management/supervision failure to properly staff the project extra time and acceleration.Lim et al (1995) studied factors affecting productivity in the construction industry in Singapore. Their findings indicated that the most important problems affectingproductivity were worry with recruitment of supervisors difficulty with recruitment of workers high rate of labour turnover absenteeism from the work site and communication problems with foreign workers. Olomolaiye et al (1996) studied factors affecting productivity of craftsmen in Indonesia, with their findings indicatingcraftsmen in Indonesia spent 75 % of their time working productively. Five specific productivity problems were identified ie lack of materials rework absenteeism lack of equipment and tools.Kane et al (cited in Herbsman et al, 1990) separate factors affecting construction productivity into two main groupings technological factors and administrative factors.The technol ogical factors encompass those related mostly to the design of the project the administrative group factors relate to the management and construction of the project. Technological factors comprise sub-groups such as design factors, material factors and location factors. Administrative factors comprise sub-groups, such as construction methods and procedural factors, equipment factors, labour factors, and social factors. Heizer and Render (1990) classified factors influencing site productivity into 3 groups labour characteristic factors project work conditions factors and nonproductive activities. Olomolaiye et al (1998) stated that factors affecting construction productivity are rarely constant, and may vary from country to country, from project to project, and even within the same project, depending on circumstances. They classified factors influencing construction productivity into 2 categories external and internal, representing those outside the control of the firms management, a nd those originating within the firm.. External factors included the nature of the industry, construction client knowledge of construction procedure, weather, and level of economic development. Internal factors included management, technology, labour, and labour unions. Enshassi et al 2006, Enshassi et al 2007, and Al Haddad 2007 stated that among the problems which the Palestinian construction industry is facing are material supply schedules and project scheduling techniques. Although a number of training courses were conducted to local contractors, these training efforts did not focus enough on the abilities to use project scheduling techniques such as Microsoft project and Primavera. Therefore training effort should also be tailored to improve methods of studying productivity and ways of productivity improvement on construction sites.The important productivity rate in project schedulingThe duration of construction project is a key factor to consider before starting a new project which is it can be determine project success of failure. Despite the uncertainty and risk level is very high in construction industry, current construction planning which is more relies on traditional deterministic scheduling method is still not clearly ascertain the level of uncertainty involved in the project. Subsequently, it can prolong a projects duration and cannot be completed within the allocation time of the project (Lee, et al., 2009).Construction projects are subjected to changes which it require constant performance monitoring and follow-up schedule updates. Project manager must take proactive attitude to analyze project data and to predict potential problems and delay in order to make timely decisions and to reduce the negative impact on cost and schedule (Hwang and Liu, 2005).Planning in construction is a complex and iterative process. A plan usually is prepared based on the estimates by the participants actual commitment. Therefore, construction productivity plan pla ys a significant role in the process. Based on Parisi, (2008), in estimating labor, there are several key factors that should be consideredProductivity of its field forces sexual union labor agreements and requirementsPast experience with the owner, designer, and construction managerLabor availabilitySpecialty tradesTherefore, if the actual construction work deviates from the anticipated plan, once the contract is sign and the project is underway, several situations may result as belowThe job may take more time because the progress is not being make at the rate projected in the original baseline schedule and thus, project completion must be extended. (In such cases, acceleration of the remaining activities may be implemented to recover time)More hours of labor may be required to install the work items because materials are not being installed by the contractors work force at the productivity rates (the anticipated quantities of material to be installed per hour) same as estimated i n the original bid.An overrun of both time and labor may occur.In order to succeed, the companies must make a phase affirmative action into the total management of productivity through a formalized, documented process such as depicted in Figure 2.0. The process should be started with historical productivity analysis. The knowledge that gained from this processes should then be utilized to forecast and manage future productivity. The supervisor that involved in this process must implement and monitor the predetermined productivity values. Only then the companies can be more competitive and successful in todays global marketFigure 2.0 A model to manage construction productivityConstruction industry seemed as low sector when there is low technology and low skilled employments occur. According to Saad, (2002), in order to raise level of construction productivity, it is recommended that the projects should have the following features spicy degree of standardizationDesign is preferred to use pre-fabricated units or pre-assemble forming systemBuilding system should be easy and simple to construct and repetitive hygienic managed construction methods with details planning and specificationHigh level of mechanized methods and skilled workersRoof worksRoof is a basic human need is for shelter, which for most of us consists of a few walls and a roof over our heads. Roofs come in many shapes and sizes. One of the main reasons for having a roof is to save up out rainwater and snow. The selection of roof is based on the following characteristicsStabilityProtection from the sun, weather, wind and rainDurablityHeat resistanceBrightness and ventilation systemBeautyConstruction of roof must be strong and able to support the load and stressed that going to happen. The load that is attributable to roof, firstly is deceased load which is the weight of the roof trusses, roof covering secondly is live load which is consists of tools, equipment, workers, rain water and lastly is wi nd load. Wind is a major stress to the roof which is difficult to forecast accurately.Roof stability is depends on the support such as roof trusses, column, walls, beams and foundation of the building.Design of roof also takes into account the respective functions of the building. Building for residential and office should have a comfortable situation in terms of condition, light, air and dam parts sounds. industrial buildings and warehouses may require heat insulation on the roof to maintain the same conditioning in buildings. Traffic in the building to allow use of the pillars supporting the roof of the short-range distance. Roof for theater and stadium, must be supported by long span of roof trusses and the support in the meat will distrupt the view and noise and sound effect protection from the audience.Productivity work to be consider in roof worksThe productivity works to be considered in this study as belowInstallation of roof trusses (cold form)Installation of insulationIns tallation of roof covering (concrete roof tiles and metal decking) no. of workers in groupDaily Productivity (m2)METHODPRODUCTIVITY OF ONE WORKING DAYHandlingHalf MechanizedFull Mechanized analysisFrom the literature review of the productivity in construction is important especially to provide accurate duration of task in building project scheduling.RerefencesDolman, B., Parham, D., Zheng, S. (2007), arouse Australia match US productivity performance?, Retrieved May 7, 2007, from http//www.pc.gov.au/ military mission/work/productivity/publications/reports.html.Diewert, W. E. and Lawrence, D. (2006), Measuring the contributions of productivity and terms of trade to Australias economic welfare, Retrieved May 7, 2007, from http//www.pc.gov.au/commission/work/productivity/publications/reports.html.Oglesby, C.H., Parker, H.W. and Howell, G.A., (1989), Construction productivity improvements, McGraw Hill, bran-new YorkAdrian, J.J. (1993), Construction Estimating An accounting and produc tivity approach 4th Edition, 1993Hwang, S. and Liu, L.Y. (2005), Proactive project control using productivity data and time series analysis, Computing in Civil Engineering 2005Thomas, H.R. and Mathew, C.T., (1986), An analysis of the methods for measuring construction productivity, SD 13, Construction Industry Institute, The University of Texas.Whiteside, J.D., (2006), Construction Productivity, AACE International Transaction, 2006Picard, (2005), Construction productivity qualifications, Cincinnati, Ohio, USAProkopenko, J.,(1987), Productivity management, Geneva International Labor Office.Jugdev, K., Thomas, J. and Delisle, C., (2001), Rethinking project management old truths and new insight, International Project Management ledger, 7(1), pp. 36-43Uusi-Rauva, E. and Hannula, M., (1996), Measurement A tool for productivity Improvement, 9th International Working Seminar on Production Economics, Innsbruck, pp. 13-29Halligan, D.W., Demsetz, L.A., Brown, J.D. and Pace, C.B., (1994), Action-response model and loss of productivity in construction, Journal of Construction Engineering and Management, Vol. 120 no 1, March 1994Teicholz, P., (2004), Labor productivity declines in the construction industry Causes and remedies, AECbytes Viewpoint 4, April 14 2004.Tucker, W.W., (2003), Construction Productivity Study Summary, Eastern Michigan University, 2003.Choy, C.F., (2008), Productive efficiency of Malaysian construction sector, Built-Environment Department, Faculty of Engineering and Science, University Tunku Abdul Rahman, Malaysia.Lee, H.S., Shin, J.W., Park, M. and Ryu, H.G, (2009), Probabilistic duration estimation model for high-rise structural work, Journal of Construction Engineering and Management, December, 2009Hwang, S. and Liu, L.Y. (2009), Predicting short term productivity I Contemporaneous time series and forecasting Methodologies, Journal of Construction Engineering and Management, December, 2009Sonmez, R. and Rowing, J.E., (1998), Construction labo r productivity modeling with neutral network, Journal of Construction Engineering and Management, December, 124(6), 498-504Portas, J. and AbouRizk, S. (1997), Neutral network model estimating construction productivity, Journal of Construction Engineering and Management, 123(4), 399-410Everett, J.G. and Fargahl, S. (1994), Learning curve predictors for construction field operations, Journal of Construction Engineering and Management, 120(3), 603-614Abdelhamid, T.S. and Everett, J.G., (1999), Time series analysis for construction productivity experiments, Journal of Construction Engineering and Management, 125(2), 87-95NIST, (2006), Engineer statistic handbookOglesby, C.H., Parker, H.W., and Howell, G.A., (1989), Productivity improvement in construction, McGraw-Hill, New York.Sweis, G.J., (2000), Impact of conversion technology on productivity in masonry construction, PhD dissertation, Northwestern University, Evanston, III.Interface Consulting International, Inc.(ICII), 2009Parisi, R .F., (2008), When the best-laid plans go astray A primer on labor productivity, not bad(p) Project Management, Inc.Saad, D.A, (2002), Standard labor productivity of reinforced concrete building structures and factor affecting on it, Thesis presented to university of Technology, IraqFACTORS AFFECTING LABOUR PRODUCTIVITY IN BUILDINGPROJECTS IN THE GAZA STRIPAdnan Enshassi1, Sherif Mohamed2, Ziad Abu Mustafa1 and Peter Eduard Mayer3