Factors affecting the fluctuation of labour productivity in the construction projects

The objective of this study have been achieved through study 233 questionnaires and theresults of analysis of 46 variables considered in questionnaire show that, there are fivemain facto

International School of Business

-Bui Trung Kien

FACTORS AFFECTING THE FLUCTUATION OF LABOUR PRODUCTIVITY

IN THE CONSTRUCTION PROJECTS

Ho Chi Minh City - 2012

UNIVERSITY OF ECONOMICS HO CHI MINH CITY

International School of Business

-Bui Trung Kien

FACTORS AFFECTING THE FLUCTUATION OF LABOUR PRODUCTIVITY

IN THE CONSTRUCTION PROJECTS

ID: 60340102

SUPERVISOR: Dr CAO HAO THI

Ho Chi Minh City - 2012

Firstly, I would like to express my deepest appreciation to my supervisor Dr Cao HaoThi for his professional guidance, valuable advice, continuous encouragement, andmotivated support that made this thesis possible

I would like to extend deep senses of gratitude to Prof Nguyen Dinh Tho and lecturerswho have taught and transferred me valuable knowledge and experience during theperiod of Master of Business course at International School of Business

Special thanks, to all of my dear friends in MBUS 2010 class, who gave me usefulmaterial, response and experience to conducting this study

I would like to express my grateful thanks to my friends and all the constructioncompany in Vietnam who participated in filling the questionnaires and provided thevaluable information for this study

Personally, I wish to express my deep gratitude to my parents, my wife, sister andbrother for their spiritual support and encouragement during the time of study

Ho Chi Minh City, Vietnam,

12 Dec 12

Bui Trung Kien

ABSTRACT

Productivity has an important role to help construction companies to be competitive,achieve set goals, meet stakeholder and value propositions The objectives of thisresearch are to identify the factors affect to the Labor Productivity Fluctuation inconstruction project in Vietnam, to access the impact strength of influenced factors onthe fluctuation of labor productivity and to suggest recommendations to reduce thefluctuation of labor productivity

The objective of this study have been achieved through study 233 questionnaires and theresults of analysis of 46 variables considered in questionnaire show that, there are fivemain factors positively affect to Labor Productivity Fluctuation in construction project.They are Supervision factor, Motivation factor, Workforce factor, Material/Equipmentfactor and Schedule factor After conducting Multiple Linear Regression and ANOVAanalysis, the model of study have been indentified which could explains 68.7 % of thetotal variance in Labor Productivity Fluctuation and ANOVA testing result also showsthat there are significant different among project characteristic group on LPF

The results of this study recommend that construction companies have to conduct labourproductivity study in their project to reduce Labour Productivity Fluctuation It

is important to have training program to increase labour skill, improve laborcommitment and the relationship among worker by increasing labor benefit and teambuilding program It also suggested that the planning software should be used in theproject to have a good planning work to reduce the frequency of working overtime andmake the labor more productivity

TABLE OF CONTENT

ACKNOWLEDGMETS i

ABSTRACT ii

TABLE OF CONTENT iii

LIST OF FIGURES vii

LIST OF TABLES viii

LIST OF ABBREVIATIONS x

CHAPTER 1: INTRODUCTION .1

1.1 Statement of the problem 1

1.2 Objective of the study 2

1.3 Scope of the study 2

1.4 Research contribution 2

1.5 Research Structure 3

CHAPTER 2: LITERATURE REVIEW 5

2.1 Definition related to project and project management 5

2.1.1 Project 5

2.1.2 Project Management 5

2.2 Definitions related to productivity 6

2.2.1 Productivity 6

2.2.2 Labor Productivity 7

2.2.3 Total Productivity 8

2.2.4 The formulation for the fluctuation of labor productivity 9

2.2.5 Construction productivity 10

2.3 Factors affecting construction productivity 10

2.4 Factor and indicators affect to labour productivity fluctuation 17

2.4.1 Factor related to workforce 17

2.4.2 Factor related to management team 18

2.4.3 Factor related to motivation 18

2.4.4 Factor related to schedule compression 19

2.4.5 Factor related to material/equipment 20

2.4.6 Factor related to supervision 22

2.4.7 Factor related to safety 23

2.5 Project characteristics 24

2.6 Conceptual framework 25

CHAPTER 3: METHODOLOGY 27

3.1 Research process 27

3.2 Sampling design 28

3.2.1Population 28

3.2.2 Sample size 28

3.3 Measurement scales 29

3.4 Questionnaire design 29

3.5 Pilot survey 30

3.6 Data collection 31

3.7 Descriptive statistics 31

3.8 Reliability analysis 31

3.9 Exploratory analysis 32

3.10 Multiple regression analysis 32

3.11 ANOVA analysis 32

CHAPTER 4: DATA ANALYSIS 33

4.1 Sample descriptive statistics 33

4.2 Reliability analysis 36

4.3 Exploratory factor analysis 39

4.4 Revised the research model 43

4.5 Multiple regression analysis 44

4.5.1 Correlation testing 44

4.5.2 Multiple linear regression analysis 45

4.5.2.1 Theory model 45

4.5.2.2 Result on the linear regression analysis 45

4.5.3 Hypothesis testing 47

4.5.4 One-Way ANOVA Analysis in project characteristic 49

4.5.4.1 One-Way ANOVA testing in type of project 49

4.5.4.2 One-Way ANOVA testing in project ownership 51

4.5.4.3 One-Way ANOVA testing in project budget 53

4.5.5 Results of ANOVA testing on project characteristics 53

4.6 Summary of data analysis result 53

CHAPTER 5: RECOMMENDATION AND CONCLUSION 55

5.1 Research finding 55

5.2 Managerial implications 56

5.3 Limitations and future research 57

APPENDICES 61

Appendix A: Questionnaire (English Version) 63

Appendix B: Questionnaire (Vietnamese Version) 69

Appendix C: First time running- Eigenvalues 76

Appendix D: First Time Running – Factor Loadings 77

Appendix E: Charts of Multiple Regression Analysis 79

LIST OF FIGURES

Figure 2.1: Factor model of construction labor productivity 11

Figure 2.2: Factors that are statistical significant 12

Figure 2.3: External affects to construction on-site productivity 13

Figure 2.4: Internal affects to construction on-site productivity 13

Figure 2.5: Workforce factor and LPF 19

Figure 2.6: Management team factor and LPF 19

Figure 2.7: Motivation factor and LPF 20

Figure 2.8: Schedule compression factor and LPF 21

Figure 2.9: Material/Equipment factor and LPF 22

Figure 2.10: Supervision factor and LPF 23

Figure 2.11: Safety factor and LPF 24

Figure 2.12: Conceptual framework 25

Figure 3.1: Research process 27

Figure 4.1: Revised conceptual model 43

Figure 4.2: Final research model 53

LIST OF TABLES

Table 2.1: Factor affecting on construction workforce productivity 14

Table 2.2: Factor affecting on labor productivity 16

Table 4.1: Mode of data collection 33

Table 4.2: Distribution of respondents’ position 34

Table 4.3: Type of project 34

Table 4.4: Ownership of project 35

Table 4.5: Total budget of project 35

Table 4.6: Rejected variables 36

Table 4.7: Reliability analysis result 37

Table 4.8: KMO and Bartlett's Test 40

Table 4.9: Total variance explain of factor analysis 40

Table 4.10: Factor analysis results 41

Table 4.11: Correlation analysis result 44

Table 4.12: Model summary of multiple linear regression analysis 46

Table 4.13: ANOVA of multiple linear regression analysis 46

Table 4.14: Coefficient of multiple linear regression analysis 47

Table 4.15: Hypothesis summary 49

Table 4.16: Descriptive for type of project group 50

Table 4.17: ANOVA for type of project group 50

Table 4.18: Descriptive for project ownership group 51

Table 4.19: ANOVA for project ownership group 51

Table 4.20: Descriptive for project budget group 52

Table 4.21: ANOVA for project budget group 52

Ho Chi Minh CityKaiser-Meyer-OlkinLabour productivity FluctuationMarket Research Society

Project Management Body of Knowledge

CHAPTER 1: INTRODUCTION

1.1 Statement of the problem

The construction industry has an important role in the developed and developingcountries In the Vietnam, construction industry is growing very strongly and has gainedmany significant achievements The General Statistic Office of Vietnam (2011) reportedthat it accounts for about 6.41 % of gross national product and 6.4 % of totalemployment The expansion of construction activities has generated a lot of jobs forskilled, semi-skilled, and unskilled labour, but beside with this, Vietnam’s laborproductivity remains low against other Southeast Asian countries despite witnessing anon-year rise in the total productivity of 5.1% as showed in the Vietnam’s labour andsocial trends report (Institute of Labour Science and Social Affairs, 2010)

A successful construction project is one that achieves the intended objectives in terms ofcost, time, quality and safety This is possible only when the planned levels ofproductivity can be attained However, productivity, or lack of it, is perhaps one of themain problems confronting the construction industry, the construction firm and theconstruction project As a consequence of the importance of the construction industry,the nature of construction projects and the available economic resources, more emphasisshould be given to improving productivity

Productivity enables an organization to be competitive, achieve set goals, meetstakeholder value propositions and maintain strategic and financial health At theindustry level, productivity enables the sector to maintain satisfied clientele, attractinvestment, remain viable and contribute to the economic growth and well-being of thenation (Durdyev and Mbachu, 2011) Understanding critical factors affecting thefluctuation of labor productivity is very necessary to improve the efficient ofconstruction project likes reduce total cost and time, and it could increase the

competitive advantages of the construction company in Vietnam toward foreignconstruction company All the above things leads this study to raise the questions “Whatare the factors affecting labor productivity fluctuation in the construction” and “How toevaluate the effects of this factor on the fluctuation of labor productivity” To answersthese questions, it necessary to conduct the topic Factors Affecting the Fluctuation ofLabor Productivity in the Construction Projects

1.2 Objective of the study

This study is conducted to achieve the following objectives

- To identify factors affecting to the fluctuation between real and planed labor

productivity of construction projects

- To assess the impact strength of these factors on the fluctuation of labor productivity

- To analysis the difference in Labor Productivity Fluctuation due to Project

Characteristics

1.3 Scope of the study

The study will be conducted base on the accomplished construction projects in Vietnamfrom 2002 until now, and more focus in HCMC The respondents will be the personwho has a important role in the project such as clients, contractors, project managers,construction managers, foreman, chief engineers … and has had experience in managingspecific construction project

1.4 Research contribution

The research results can be used to:

- Help Construction Companies in Vietnam to have an overview on Labor Productivity

in construction project

- Help Construction Companies in Vietnam to have deeply awareness about the mainfactors affect to the fluctuation of labor productivity in construction project and they canmanage Labor Productivity more effectively

- Help them in building a suitable Labor Productivity Plan with its characteristic and condition

- Be a reference for new investors who want to invest in construction industry in

Chapter 2 – Literature Review

This chapter will present recent definitions related to project management, productivity,labor productivity and construction productivity Base on the previous studies, thissection also identify the factors affecting to labor productivity in construction project,states the Hypothesis and proposed the research model for this study

Chapter 3 – Methodology

This chapter presents the research process and the methodology that will be used forempirical testing of the research model which has been developed in chapter 2

Chapter 4 – Data Analysis

This chapter presents the data analysis result, this is the most significant part of thestudy as it will contain the data analysis including of Sample Descriptive Statistics,Reliability Analysis, Exploratory Factor Analysis, Multiple Regression Analysis andANOVA Analysis to provide a very comprehensive picture about the relationship offactors affecting to the fluctuation of labor productivity in construction project inVietnam

Chapter 5 – Conclusion and Recommendation

With results from analyzing data collected in chapter 4, a conclusion as well as theobjective required is established The finding reconfirms the factors affecting to thefluctuation of labor productivity in construction project Finally, recommendations arebrought to improve labor productivity in construction project and give direction forfuture research

CHAPTER 2: LITTERATURE REVIEW

This chapter presents a review of relevant literature related to factors affecting laborproductivity and consists of definitions related to project and project management,definitions of productivity, total productivity and construction productivity This chapteralso states the hypotheses and propose conceptual model for this study

2.1 Definition related to project and project management

2.1.1 Project

A guide to the Project Management Body of Knowledge (2008, p 5) has defined aproject as “a temporary endeavor undertaken to create a unique product, service, orresult The temporary nature of projects indicates a definite beginning and end The end

is reached when the project’s objectives have been achieved or when the project isterminated because its objectives will not or cannot be met, or when the need for theproject no longer exists Temporary does not necessarily mean short in duration.Temporary does not generally apply to the product, service, or result created by theproject; most projects are undertaken to create a lasting outcome”

Lake (1997) defined a project as “a temporary endeavor involving a connected sequence

of activities and a range of resources, which is designed to achieve a specific and uniqueoutcome and which operates within time, cost and quality constraints and which is oftenused to introduce change”

2.1.2 Project management

Project management has been defined by PMBOK (2008, p.8) as “The application ofknowledge, skills, tools and techniques to project activities to meet project requirement”

Yuong (2007) defined project management as “a dynamic process that utilizes theappropriate resources in a controlled and structured manner to achieve some clearlydefined objectives indentified as strategic needs”

2.2 Definitions related to productivity

2.2.1 Productivity

Prokopenko (1987) defined that “productivity is the relationship between the outputgenerated by a production or service system and the input provided to create this output.Thus, productivity is defined as the efficient use of resource – labors, capital, land,materials, energy and information – in the production of various goods or services.Productivity can also be defined as the relationship between results and the time it takes

to accomplish them Time is often a good denominator since it is a universalmeasurement and it beyond human control The less time taken to achieve the desiredresult is the more productive the system” Prokopenko also stated that “regardless thetype of production, economic or political system, the definition of productivity remainsthe same Thus, though productivity may mean different things to different people, thebasic concept is always the relationship between the quantity and quality of goods orservices produced and the quantity of resources used to produce them”

Eatwell and Newman (1991) defined productivity as a ratio of some measure of output

to some index of input use Put differently, productivity is nothing more than arithmeticratio between the amount produced and the amount of any resources used in the course

of production This conception of productivity goes to imply that it can indeed beperceived as the output per unit input

International Labor Office (as cited in Mostafa, 2003) described productivity as

“Productivity is a comparison between how much you have to put in to the projects in

terms of manpower, material, machinery or tools and the result you get out of theproject Productivity has to do with the efficiency of production Making a site moreproductive means getting more output for less cost in time, Productivity covers everyactivity that goes into completing the construction site works, from the planning state tothe final site clearing, if the contractor can carry out these activities at lower cost in lesstime with fewer workers or with less equipment the productivity will be improved”.

Overall, productivity could be defined as the ratio of outputs to inputs

Productivity = Outputs / Inputs

Where, outputs could be in units or dollar value of product or service, revenue generated

or value added Input could be in units or dollar value relating to labor, equipment,materials, capital, so it will be very important to specify the inputs and outputs to bemeasured when calculating productivity

2.2.2 Labor Productivity

At the national level, labor productivity is computed by taking the entire economicallyactive population as the input and the total value of goods and services produced as theoutput (Prokopenko, 1987)

National productivity = GNP/Population

It is general knowing that almost all the definitions of productivity centre on ‘outputs’and ‘inputs’ Unfortunately, definition of either output or input or both may sometimespose more difficulty to the understanding of what productivity is For output, it is in theform of goods if visible and services if invisible Input on the other hand is less easilydefined Since production (creation of goods and services) is a team effort thereby

making the demand for inputs to be interdependent, various elements (inputs) areinvolved in the production of output This makes the definition of input more complexthan that of output To ease this problem of defining inputs, it is common a practice toclassify inputs into labor (human resources), capital (physical and financial assets), andmaterial Again, in an attempt to circumvent the difficulty of defining inputs,productivity is sometimes defined as goods and services produced by an individual in agiven time In this sense, time becomes the denominator of output with the assumptionthat capital, energy and other factors are regarded as aids, which make individuals moreproductive

Freeman (2008) stated that Labor productivity is equal to the ratio between a volumemeasure of output (gross domestic product or gross value added) and a measure of inputuse (the total number of hours worked or total employment)

Labor productivity = volume measure of output / measure of input use

“The volume measure of output reflects the goods and services produced by theworkforce Numerator of the ratio of labor productivity, the volume measure of output ismeasured either by gross domestic product (GDP) or gross value added (GVA) Themeasure of input use reflects the time, effort and skills of the workforce Labor input ismeasured either by the total number of hours worked of all persons employed or totalemployment”

2.2.3 Total Productivity

Total productivity can be described as the overall measure of economic effectiveness onthe basis of output per unit of all resource(s) utilized In the last decade, there has been adefinite move towards its utilization and that is the ratio of total output to the sum of allinput factors (Stainer, 1997) as Equation [2.1]

2.2.4 The formulation for the fluctuation of labor productivity

The fluctuation of labor productivity is the difference between actual labor hours and planedlabor hours of project/work package per actual labor hours of project/work package, so theformulation the fluctuation of labor productivity will be calculated as as Equation [2.2]

W A

W P

[2.2]

*100

W P

WA = Total actual labor hours of project/work package

WP = Total planed labor hours of project/work package

If L <0 : Actual labor productivity is higher than planed

2.2.5 Construction productivity

Productivity in construction is often broadly defined as output per labor hour Sincelabor constitutes a large part of the construction cost and the quantity of labor hours inperforming a task in construction is more susceptible to the influence of management

than are materials or capital, this productivity measure is often referred to as labor

productivity However, it is important to note that labor productivity is a measure of the

overall effectiveness of an operating system in utilizing labor, equipment and capital toconvert labor efforts into useful output, and is not a measure of the capabilities of laboralone For example, by investing in a piece of new equipment to perform certain tasks inconstruction, output may be increased for the same number of labor hours, thus resulting

in higher labor productivity (Hendrickson, 1998)

Hendrickson also presented that construction output may be expressed in terms offunctional units or constant dollars In the former case, labor productivity is associatedwith units of product per labor hour, such as cubic yards of concrete placed per hour ormiles of highway paved per hour In the latter case, labor productivity is identified withvalue of construction (in constant dollars) per labor hour The value of construction inthis regard is not measured by the benefit of constructed facilities, but by constructioncost Labor productivity measured in this way requires considerable care ininterpretation For example, wage rates in construction have been declining in the USduring the period 1970 to 1990, and since wages are an important component inconstruction costs, the value of construction put in place per hour of work will decline

as a result, suggesting lower productivity

2.3 Factors affecting construction productivity

There are numerous events that can cause a loss of labor productivity Thomas andZavrski (as cited in Rojas, 2008) had developed a factors model, which graphically

show in Figure 2.1 There are two broad categories related to the work that affect laborproductivity These are work to be done and the environment in with the work is doneand it can be viewed as either contributing to or inhibiting this conversion process Thefigure shows that the inputs in terms of labor hours are converted to outputs orquantities of work through the application of some work method.

Article I.

Indirect

Article III Article V Article VII Article IX S

Causes

hanges vertime ncrease Manning hift Work

Article XI Article XIII Article XV. Article XVII. Article XXIX.

Work Environ Article XIX. Article XXI Article XXIII Article XXV Article XXVII.

omponent Size pecs & Qual Req ork Content esign Features ork Scope

Figure 2.1: Factor model of construction labor productivity

Source: Rojas (2008).

Homyun Jang et al (2009) suggested variables affecting to labor productivity and havebeen identified 25 critical variables and grouped to 4 groups of factors, namely workmanagement, work technique, work characteristic and worker component as shown inFigure 2.2.

Work characteristic Worker component

Worker sense of responsibility

Work quantity

Figure 2.2: Factors that are statistical significant

Source: Homyun Jang et al (2009)

Labor productivity and the factors that affect it have been studied extensively in thefield of construction research Durdyev and Mbachu (2011) indentified 56 variables thataffect construction productivity, and categorized them in to 8 factors of internal andexternal Figure 2.3 and Figure 2.4 Figure 2.3 represents external constraint with threegroups of factor: Unforeseen events, statutory compliance and other external forces.Figure 2.4 shows the internal constraints with five groups of factors: Project

characteristics, project finance, workforce, project management and technology/process

Inclement weather

Ground condition

necessitating revisions.

On-site accident/ Act of

God Natural Disaster

Health & Safety in employment

Act Resource management Act

Local Authority bylawa

Construction contracts

Building/ Act, consent, regulation.

Employment relation Act.

Consumer guarantees Act.

Fair trading Act

Fluctuations in material prices Fluctuation in exchange rate Energy crises/costs.

External group of

Interest rate/cost of capital

Market conditions and level of

factors competitions in the industry for jobs

Frequency change in government policies/legislations on construction Rapid technological advances

litigations/adversarial relations.

Figure 2.3: External affects to construction on-site productivity

Source: Durdyev and Mbachu (2011)

Site condition

Project complexity

Build ability issue

Site location and environment

Type of procurement adopted

Late of payment

Rework

Under valued work/poor estimation

Dispute and litigation costs

Lenders’ high interest charges

High insurance premiums

Inadequate supply or high cost

Adequacy of planning and risk management process Coordination, supervision, performance monitoring & control

Project Organizational culture Relationship management

Competencies of the project team Project management style

Frequency of design changes Client’s over influence on the

Level of commitment

Level of empowerment

Level of skill and experience

Level of familiarity with current

job and conditions

Level of involvement of direct labor

or subcontract

Workforce absenteeism

Level of staff turnover/churn

rate Health of the workforce.

Suitability or adequacy of plant & equipment

Technology employed Lack of awareness of or

training on new technologies

Resistance to accept new technologies Inadequate IT infrastructure and application in construction industry

Figure 2.4: Internal affects to construction on-site productivity

Source: Durdyev and Mbachu (2011)

Kazaz et al (2008) determined four factors and it’s variables as presented in Table 2.1.

Table 2.1: Factor affecting on construction workforce productivity

Socio-psychological factors Organizational Factors

Health and safety conditions Material management

Giving Responsibility Occupation education and training Sharing problems and their results Crew size and efficiency

Social activity opportunities Firm reputation

Worker participation indecision Relaxation allowances

making

Distance from home

Distance from population centres

Economic factor Physical factors

Incentive payments and financial Weather conditions

Shift Site congestion

Source: Kazaz et al., (2008)

Enshassi (2007) classifies factors effecting productivity in the construction in to 10groups, namely: factors associated with the internal workforce, factors associated withleadership, factors associated with work motivation factor associated with time, factorsassociated with materials and equipment, factors related to supervision, factors related toproject characteristic, factors related to security, factors related to quality, and externalfactors

Soekiman et al (2011) identified 113 variables affecting construction labor productivityand these variables were grouped into 15 groups of factors according to theircharacteristics, namely: Design, execution plan, material, equipment, labor, health andsafety, supervision, working time, project factor, quality, financial, leadership andcoordination, organization, owner/consultant, external factor

Nabil Ailabouni et al (2007) indentified 32 significant variables affecting theproductivity in the construction industry then grouped into 4 group base on theircharacteristic, namely: Environment factors, organizational factors, group dynamics,personal factors

Makulsawatudom and Margaret (2001) indentified 23 variables Henry et al (2007)suggested 36 variables: Incompetent supervisor Lack of skill of the workers, Rework,lack of tool/equipment, poor construction method, poor communication, stoppagesbecause of work being rejected by consultant, political insecurity, tool/equipmentbreakdown…

In summary, based on the previous research and after refinement, 46 variables areselected and grouped to 7 groups according to their characteristics, namely: Workforce,management team, motivation, schedule compression, material/equipment, supervision,safety and All of them are shown in Table 2.2

Table 2.2: Factor affecting on labor productivity

No Factor Variables/Measurement scale Code Author/Year

2.4 Factors and indicators affect to labour productivity fluctuation

2.4.1 Factor related to workforce

Enshassi et al (2007) identify 8 variables related to workforce factor and the result showthat the most important variable negatively affecting the productivity is lack of laborexperience, followed by labor disloyalty, labor dissatisfaction, misunderstanding amonglabor, lack of competition, increase in laborer age, labor absenteeism, and labor personalproblem Duryev et al (2011) also identify 8 sub-factors affect to labor productivity withlevel of impact is descending as level of skill and experience of the workforce,motivation/commitment, level of familiarity with current job and conditions, workforceabsenteeism, level of staff turnover and health of the workforce These variables abovealso is supported by Kazaz et al (2008), Homyun Jang et al (2009), Makulsawatudom et

al (2001), and Soekiman et al (2010) Base on the previous research above this study hasbeen refined and collected 8 sub-factors related to the main factor of workforce andstated a hypothesis as following:

Hypothesis H 1 : There is a positive impact of workforce factor on the fluctuation of

- Increase of labourer age

- Poor health of the workers

- Poor relations among workers

Figure 2.5: Workforce factor and LPF

2.4.2 Factor related to management team

Enshasi et al (2007), Homyun Jang et al (2009), Ailabouni et al (2006) identified thecore elements effect to Labor Productivity, including: bad leadership skill, poor relationsbetween labor and superintendents, and lack of labor surveillance Base on that previousresearch, this study stated a hypothesis related to management team factor as following:

Hypothesis H 2 : There is a positive impact of management team factor on the

fluctuation of labor productivity

Hypothesis H2 is presented in Figure 2.6

Management team

- Bad leadership skill

H2+

- Lack of periodic meeting with labor

Figure 2.6: Management team factor and LPF

2.4.3 Factor related to motivation

Motivation is extremely important Non motivated employees can have several negativeeffects on your business These include friction on the job, substandard output inquality, a high turnover of employees, absenteeism, tardiness, and many of thedisciplinary problems that you wish to avoid Enshasi et al (2007) identified 6 sub-factors related to motivation factor These sub-factors were placed in descending orderaccording to their importance: payment delay, lack of financial motivation system, lack

of labor recognition programs, non-provision of transport means, lack of places foreating and relaxation and lack of training sessions Durdyev et al (2011) also identified 3sub-factor related to motivation factors, that are reworks, under-valued work/poor,

late payment It also supported by the research Kazaz et al(2008) such as: on-timepayment, amount of pay, working in social insurance, incentive payments and financialrewards, discontinuity of work and union membership Base on the previous researchabove this study have been refined and collected 7 sub-factors related to the main factor

of motivation and stated a hypothesis as following

Hypothesis H 3 : There is a positive impact of motivation factor on the fluctuation of

labor productivity

Hypothesis H3 is presented in Figure 2.7

Motivation

- Lack of labor recognition program

- Poor condition of camping

- Lack of place for eating and relaxation

Figure 2.7: Motivation factor and LPF

2.4.4 Factor related to Schedule Compression

In a typical construction project, a contractor may often find that the time normallyexpected to perform the work has been severely reduced The reduction of timeavailable to complete a project is commonly known throughout the construction industry

as schedule compression Schedule compression is a problem because it negativelyimpacts labor productivity in various ways, and it becomes a source of dispute betweenthe owners and contractors Base of the previous research of Kazaz et al (2008),Durdyev et al (2011), Enshasi et al (2007), Ailabouni et al (2006), Soekiman

et al (2010), and Homyun Jang et al (2009) this study have been refined and collected 5sub-factors related to the main factor of Schedule Compression and stated a hypothesis

as following:

Hypothesis H 4 : There is a positive impact of schedule compression factor on the

fluctuation of labor productivity

Hypothesis H4 is presented in Figure 2.8

Schedule compression

- Working 7 days per week without taking a holiday

H4+

- Poor work planning

- Overcrowding

Figure 2.8: Schedule compression factor and LPF

2.4.5 Factor related to Material/Equipment

Material and Equipment are very important, as without them work cannot be doneprogressively or to the required quality Makulsawatudom et al (2001) indentified thatlack of material and lack of equipment were highlight as the most critical factoraffecting to productivity because of material are essential for the construction process.Kazaz et al (2008) stated that lack of material is a universal problem and has asignificant degrading effect on site productivity for both developed and developingcountries Improper material planning and on site transportation difficulties are amongstthe resource of lack of material The case appeared as a result of material shortage and itlikely the most considerable part of material management practices related with laborperformance When adequate supply of material is not possible, workers try not toexhaust their current stockpile of supplies, so they may slow down

their pace or output in anticipation of a delivery, resulting in idle times and costoverruns.

Enshassi et al identified 3 sub-factors related to material/equipment factor, includingmaterial shortage, tool and equipment shortages and unsuitability of material storagelocation Homyun Jang et al (2009) also suggested 11 sub-factors related tomaterial/equipment, they are equipment condition, number of equipment, equipmentservice time, equipment transport environment, equipment procurement, equipmentperformance, material condition, material quantity, materials transport environment,material procurement and material applicability These sub-factors about also supported

by Henry et al (2007), Ailabouni et al (2006) and Soekiman et al (2010) Base on theprevious research above and adapt with Vietnamese construction project condition, thisstudy have been refined and collected 6 sub-factors related to the main factor ofmaterial/equipment and stated a hypothesis as following

Hypothesis H 5 : There is a positive impact of material/equipment factor on the

fluctuation of labor productivity

Hypothesis H5 is presented in Figure 2.9

Material/Equipment

- Material shortages

H5+

- Lost time to find material because of poor arrangement

- Equipment and tools shortages

- Poor condition of equipment and tools

Figure 2.9: Material/Equipment factor and LPF

2.4.6 Factor related to Supervision

To follow-up and supervise labour while working is a vital aspect of any organizationbecause both it can result in extensions of project time and cost, and the quality on site

is controlled through inspection of the work completed by the gang To improve thesupervision work, it is necessary to identify the factor affect on it Enshasi et al (2007)stated that all supervision factors have a high impact on productivity, and were rankedaccording to their importance as follows: drawings and specifications alteration duringexecution; inspection delay; rework; and supervisors’ absenteeism In the study ofHenry et al (2007) also indicated the factor related to supervision group like:incompetent supervisor, poor construction method, frequency rework, incompletedrawing and design change, design complexity Makulsawadom et al (2001) indentified

7 sub-factors, including incomplete drawing, inspection delay, incompetent supervisor,long instruction time, changing order, rework The sub-factors related to supervisionfactor also supported by Kazaz et al (2008) ), Durdyev et al (2011), Homyun Jang et al(2009), Ailabouni et al (2006) Based on these previous research, and after consideringwith Vietnamese construction project condition, this study have been refined andcollected 8 sub-factors related to the main factor of supervision and stated a hypothesis

Figure 2.10: Supervision factor and LPF

2.4.7 Factor related to Safety

Safety is very important aspects of construction projects which are the most hazardousendeavors have many work-related injuries and accidents Accordingly, safety factorsmust be considered in project lifecycle from beginning of a project to its end Toimprove project safety, the definition of safety factors and determination of theirimportance are necessary In some of the previous researches several safety factors areintroduced Enshasi et al (2007) identified 7 factors under the safety group have beenplaced in descending order as follows: accidents, violation of safety precautions,insufficient lighting, bad ventilation, working at high places, unemployment of safetyofficer on the construction site, and noise This study also base on the past research ofDurdyev, Henry et al (2007), Homyun Jang et al (2009), and Makulsalsawadom et al(2001) and after considering with Vietnamese construction project condition, this studyhave been refined and collected 8 sub-factors related to the main factor of saftey andstated a hypothesis as following

Hypothesis H 7 : There is a positive impact of safety factor on the fluctuation of labor

productivity

- Unsafe working conditions

- Inadequate safety plan

- Lack of labor safety (clothes safety, …)

Figure 2.11: Safety factor and LPF

2.5 Project characteristic

According to Nitithamyong et al (2011), the project characteristic group includes projectlocation, type of owner, type of contract, type of project, project size, project cost,project duration, complexity related to design and engineering, complexity related toconstruction task However, in the condition of Vietnam, some factors above could benot easy to collect information form attendant, therefore this study will only considersuch factors: Type of owner, type of project and project value The projectcharacteristics and labor productivity fluctuation of the project are stated in hypothesis

H8

Hypothesis 8: There is a difference in Labor Productivity Fluctuation due to Project

Characteristics

2.6 Conceptual framework

The conceptual framework is presented in Figure 2.12 and consisting of 8 hypothesisesfrom H1 to H8, in there, the group factors correspond with H1 to H7 are independent andquantitative variables, it affects directly on labour productivity fluctuation, a dependentvariable Besides, Labour productivity fluctuation will also be different on projectcharacteristics (Project Type, Project Owner and Project Budget) and it is stated in H8

Project characteristic

- Project Type

- Ownership of Project

- Project Budget Workforce

H1+

8 Management team

H 3 +

Motivation

fluctuation Schedule compression

Figure 2.12: Conceptual framework