CHAPTER 2 LITERATURE REVIEW

Transcription

1 10 CHAPTER 2 LITERATURE REVIEW 2.1 GENERAL One of the most important problems in the construction industry is Time overrun. Time overrun occur in every construction project and the magnitude of these delays varies considerably from project to project. So it is essential to define the actual causes of Time overrun in order to minimize and avoid delays in any construction project. This chapter discusses about the literatures under the following heads: Time overrun (delay), types of delay, causes of time overrun, resource related factors causing time overrun, data analysis and inference from literature survey. 2.2 TIME OVERRUN (DELAY) Sanders and Eagles (2001) define delay as an event that causes extended time to complete all or part of a project. Delay may also be defined as the time overrun, either beyond the date for completion specified by the contract or beyond the extended contract period where an extension of time has been granted. The type of delay focused in this study is the time overrun beyond the date for completion specified by the contract not considering whether an extension of time has been granted.

2 11 Delay in construction is a global phenomenon (Sambasivan & Soon 2007) affecting not only the construction industry but the overall economy of countries as well (Faradi & El-Sayegh 2006). Time overrun (delay) involves multiple complex issues all of which are invariably of critical importance to the parties to the construction contract. These issues concern entitlement to recover costs of delay or the necessity to prolong the project with the consequential entitlement to recovery costs for adjustments to the contract schedules. Questions arise as to the causes of delay and the assigning of fault often evolves into disputes and litigation (Bolton, 1990). Today, many stakeholders in construction are becoming increasingly concerned about the duration of construction projects because of increasing interest rates, inflation, commercial pressures (Nkado 1995), and of litigation. Time overrun (delay) is defined as the extension of time beyond planned completion dates traceable to the contractors (Kaming et al 1997). activities; delay causing incidents may include weather delays, unavailability of resources, design delays, etc. In general, project delays occur as a result of project activities that have both external and internal cause and effect relationship (Vidalis and Najafi 2002). Choudhry (2004) and Chan (2001) defined the time overrun as the difference between the actual completion time and the estimated completion time. 2.3 TYPES OF DELAY Delays in construction are caused by several factors. Ahmed et al. (2003) grouped delays into two categories internal causes and external causes. Internal causes arise from the parties to the contract (e.g. contractor,

3 12 client, and consultant). External causes, on the other hand, arise from events beyond the control of the parties. These include the act of God, government action, and material suppliers. Bolton (1990) classifies delay as follows: Excusable but non-compensable delay - these are delays caused by occurrences which are not attributable to any of the parties. Compensable delay - these delays result from acts or omissions of the owner or someone for whose acts an owner is liable. Inexcusable delay - these delays result from a contractor's own fault or his subcontractors or material suppliers. The types of delays have impact on internal and external project process. Internal causes of delay include owner, designers, contractors, and consultants. External causes of delay may be due to utility companies, government, subcontractors, suppliers and vendors, labour and nature. Figure 2.1 presents sequential relationships of various categories of delays (Vidalis & Najafi 2002). Time overrun (Delay) Excusable Concurrent Non excusable Compensable Noncompensable Non critical Critical Figure 2.1 Sequential relationships of various categories of delays

4 Excusable Delays Excusable delays are those actions or inactions, and typically include unforeseen events. These events are part. Excusable delays, when founded, entitle the contractor to a time extension if the completion date is affected. This type of delay can also have an impact on non-critical activities which need a more detailed analysis to determine whether additional time extension is warranted, or if the reduction of float time can be justified. Excusable delays can be further classified into excusable with compensation and excusable without compensation (Abd Majid & McCaffer 1998). inactions. When contractors encounter this type of delay, they are entitled to time extension as well as monetary compensation due to the delays. An example of an excusable delay with compensation would be when an owner denies access to the site once the notice to proceed is given. Excusable without compensation are delays where neither the client nor the contractor is deemed responsible. When this type of delay is encountered, only a time extension will be warranted since there are no grounds for damages. Some examples of excusable without compensation Non-excusable Delays Nonesults of underestimates of productivity, improper project planning and scheduling, poor site management and supervision, wrong construction methods,

5 14 equipment breakdowns, unreliable subcontractors or suppliers. Consequently, this type of delay presents no entitlement to a time extension or delay damages for the contractor if the delay can be proved to have affected the whole project. The client, however, could be entitled to liquidate damages. An example of a non-excusable delay would be when a contractor fails to provide sufficient manpower to complete the job on time Concurrent Delays Concurrent delays refer to delay situations when two or more delays occur at the same time or overlap to some degree either of which, had the delays occurred alone, would have affected the ultimate completion date (Alaghbari et al 2007). Normally concurrent delays which involve any two or more excusable delays result in a time extension. When excusable with compensation and non-excusable delays are concurrent, a time extension can be issued or the delay can be apportioned between the owner and the contractor. In analysing concurrent delays, each delay is assessed separately and its impact on other activities and the project duration is calculated. The following guidelines for classifying these kinds of concurrent delays: If excusable and non-excusable delays occur concurrently, only a time extension is granted to the contractor; If excusable with compensation and excusable without compensation delays occur concurrently, the contractor is entitled to time extension, but not to damages; and If two excusable with compensation delays occur concurrently, the contractor is entitled to both time extension and damages.

6 15 An example of a concurrent delay would be if the client failed to supply detailed designs for specified machine installations (excusable delay with compensation) while at the same time, the contractor who would have installed those machines was on strike (excusable delay without compensation). In this scenario, since both excusable with compensation and excusable without compensation delays are present, the contractor would be entitled to a time extension, but not to damages. Although such guidelines are useful for the purpose of carrying out delay analysis, it is in the best interest of all parties involved in a construction project to agree, at the beginning, the definitions of such delays and accommodate them throughout the contract language. Until the development of CPM schedule analysis, there was no reliable method to differentiate the impact of the impact of contractor caused delays from client caused delays. With the sophisticated computerized techniques now available, however, it has become possible to segregate the impacts of apparently concurrent client and contractor delays (Alwi et al 2002) Compensable Delays Compensable delays are those that are generally caused by the owner or its agents. The most common form of compensable delay is inadequate drawings and specifications, but compensable delays can also arise from the owners failure to respond in a timely fashion to requests for information or shop drawings, owners changes in design or materials, and owners disruption and/or change in the sequence of the work. The contractor is entitled to both additional money and additional time resulting from compensable delays (Alaghbari et al 2007). In addition to the compensable delays that result from contract changes by change notice, there are compensable delays that can arise in other

7 16 ways. Such compensable delays are excusable delays, suspensions, or interruptions to all or part of the work caused by an act or failure to act by the owner resulting from owners breach of an obligation, stated or implied, in the contract. If the delay is compensable, then the contractor is entitled not only to an extension of time but also to an adjustment for any increase in costs caused by the delay (Al-Gahtani & Mohan 2007) Critical Delays Critical delays are delay claims that affect the progress, time, and compensation. Noncritical delays do not affect the completion date of the project. They affect the succeeding activities that are not on the critical path of the schedule. This can set back activities if they do not have a float in the schedule (Abudul-Rahman et al 2006). 2.4 CAUSES OF TIME OVERRUN Time overrun in construction projects has been a research topic for decades. Research conducted in this area is broadly divided into two streams - one stream relating to factors that cause project time overrun and the other stream relating to time overrun analysis. Some location specific work related to time overrun analysis reported by El-Razek et al (2008); Sambasivan & Soon (2007); Iyer & Jha (2005) highlighted the complexity on this issue across many countries. The first stream of literature focusing upon time overrun factors which is more relevant to this research is reviewed below. Arditi et al (1985) reported the causes of delay on Turkish publicsector construction projects in the 1970s and 1980s by surveying public agencies and contractors involved in public sector projects. This study divided the identified factors into those that are influenced by national economic policies and those that can be controlled by the public agencies and

8 17 contractors. They identified the factors that shortages of some resources; deficiencies and delays in design work, frequent change orders and considerable extra work are the most important sources of delay. While some of the causes are dependent on national economic policies, others may be overcome by measures to be taken by public agencies and contractors. Bramble & Callahan (1992) reviewed the causes of delays by looking at the responsibility of major parties to the design and construction process. They identified that owner caused delay by late release of site to the contractor, late approvals, financial difficulties, contract administration responsibilities, change orders, and inferences. The design caused problem identified by design defects, slow correction of design errors, tardy shop drawings review and delays due to test and inspection. The contractor related problem were identified as failure to evaluate the site and design, contract management problem, inadequate resources and construction defects while whether, acts as God, strikes, and labour disputes were identified as delay not caused by the design and construction parties. Mansfield et al (1994) identified 16 major factors that caused delays and cost overruns in Nigeria. A questionnaire survey was carried out with contractors, consultants and client organizations in Nigeria. They presented that the causes of delay and cost overruns in Nigerian construction projects were attributed to finance and payment arrangements, poor contract management, shortages in materials, inaccurate estimation, and overall price fluctuations. Assaf et al (1995) identified 56 main causes of delay in Saudi large building construction projects and their relative importance. Based on the

9 18 contractors surveyed the most important delay factors were: preparation and approval of shop drawings, delays in contractors progress, payment by owners and design changes. From the view of the architects and engineers the cash problems during construction, the relationship between subcontractors and the slow decision making process of the owner were the main causes of delay. However, the owners agreed that the design errors, labour shortages and inadequate labor skills were important delay factors. Chan & Kumaraswamy (1996) determined and classified the causes of construction delays in Hong Kong as seen by clients, contractors and consultants, and evaluated the relative importance of the significant factors affecting delay in productivity. They indicate that the five principal and common causes of delays are: poor site management and supervision; unforeseen ground condition; low speed of decision making involving all projects team; client initiated variations; and necessary variation of works. Ogunlana & Promkuntong (1996) conducted a study on construction delays in Thailand. They found that the problems faced by the construction industry in developing economies like Thailand could be: (a) shortages or inadequacies in industry infrastructure (mainly supply of resources); (b) incompetence/inadequacies. They recommended that there should be concerted effort by economy managers and construction industry associations to provide the necessary infrastructure for efficient project management. Odeyinka & Yusif (1997) have addressed the causes of delays in building projects in Nigeria. They classified the causes of delay as project participants and extraneous factors. Client - related delays included variation in orders, slow decision-making and cash flow problems. Contractor - related

10 19 delays identified were: financial difficulties, material management problems, planning and scheduling problems, inadequate site inspection, equipment management problems and shortage of manpower. Extraneous causes of delay identified were: inclement weather, acts of nature, labor disputes and strikes. Chan & Kumaraswamy (1998) conducted a survey to determine and evaluate the relative importance of the significant factors causing delays in Hong Kong construction projects. They analyzed and ranked main reasons for delays and classified them into two groups: (a) the role of the parties in the local construction industry (i.e. whether client, consultants or contractors) and (b) the type of projects. Results indicated that five major causes of delays were: poor site management and supervision, unforeseen ground conditions, low speed of decision making involving all project teams, client initiated variations and necessary variations of works. Mezher & Tawil (1998) conducted a survey of the causes of delays in the construction industry in Lebanon from the viewpoint of owners, contractors and architectural/engineering firms. It was found that owners had more concerns with regard to financial issues; contractors regarded contractual relationship the most important, while consultants considered project management issues to be the most important causes of delays. A comprehensive classification of causes of construction delays has been recommended by Abd Majid & McCaffer (1998). They classified the factors of causes of non - excusable delays into twelve groups: material - related delays; labour related delays; equipment - related delays; financial - related delays; improper planning; lack of control; subcontractor - related delays; poor coordination; inadequate supervision; improper construction methods; technical personnel shortages; and poor communication.

11 20 Al-Khalil & Al-Ghafly (1999) assessed the frequency of project delay in water and sewage projects, the extent of delay, and the party responsible for the delay. They found that a large number of projects experience delay, especially in medium and large size projects. Owners and consultants assigned the major responsibility for delay to the contractor but the contractor placed it mostly on the owner. On an average, the contractor is assigned the most responsibility, but when considering that part of the responsibility of the consultant and others may be transferable to the owner, the owner may carry the prime responsibility for delay. It may also be argued that the contractor is not primarily responsible because of the high xtension. The authors identified, and assessed the impact of delays on the delivery of construction projects. Time and cost overruns were found to be frequent effects of delay. management procedures and the inclusion of an appropriate contingency allowance in the pre-contract estimate were recommended as a means of minimizing the adverse effect of construction delays in Nigeria. Odeh & Battaineh (2002) studied the causes of construction delay at traditional contracts in Jordan, they used questionnaire procedure in this study; the questionnaire was distributed to a random sample of 100 contractors and 50 consultants. The study illustrated that; according to contractors, labour productivity was the most important delay factor. Inadequate contractor experience, however, was the most important delay factor to consultants. All parties generally agreed on the ranking of the individual delay factors. They agreed that inadequate contractor experience, owner interference, and financing of work were among the top five important factors. Moreover, delays caused by subcontractors, slow decision making by owners, improper planning, and labour productivity were among the top ten

12 21 important factors for both parties. Operational factors such as labor productivity, construction methods, site management, and equipment availability and failure were important to contractors than to consultants. Al-Momani (2000) carried out a quantitative analysis on construction delays by examining the records of 130 public building projects in Jordan. The result of his study indicated that the main causes of delay in construction of public projects were related to designers, user changes, weather, site conditions, late deliveries, economic conditions and increase in quantity. Aibinu & Jagboro (2002), in their study of the growing problem of construction delay in Nigeria, examined the effects of delays on the delivery of construction projects in the country. Utilizing a questionnaire survey of 61 construction projects, the authors identified, and assessed the impact of delays on the delivery of construction projects. Time and cost overruns were found to be frequent effects of delay. Acceleration of site activities coupled with improved owners' project management procedures and the inclusion of an appropriate contingency allowance in the pre-contract estimate were recommended as a means of minimizing the adverse effect of construction delays in Nigeria. Ahmed et al (2003) found that the most common type of delay is excusable compensable at 48 percent, followed by non-excusable delays with 44 percent and 8 percent for excusable non- compensable delays. In most of the cases, it is found that when the contractor has the responsibility, the type of delay is nonco They identified internal causes of delay include the causes arising from four parties involved in the project. These parties include the owner, designers, contractors, and consultants. Other

13 22 delays, which do not arise from these four parties, are based on external causes for example from the government, materials suppliers, or the weather. Frimpong et al (2003) conducted a survey to identify and evaluate the relative importance of significant factors contributing to delay and cost overruns in Ghana ground water construction projects. A questionnaire with 26 factors was carefully designed from preliminary investigations conducted in groundwater drilling projects between 1970 and 1999 in Ghana. The questionnaire was directed towards three groups in both public and private organizations: owners of the groundwater projects, consulting offices, and contractors working in the groundwater works. The questionnaire was distributed to a random sample of 55 owners, 40 contractors and 30 consultants. The result of the study revealed the main causes of delay and cost overruns in construction of groundwater projects: monthly payment difficulties from agencies; poor contractor management; material procurement; poor technical performance; and escalation of material prices. Long et al (2004) reviewed the problems on large construction projects in developing countries, a case study from Vietnam. They revealed that the problems could be grouped under five major heads; incompetent designers/contractors; poor estimation and change of management; social and technological issues; site related issues; and improper techniques and tools. Wiguna & Scott (2005) studied on the risks affecting construction delays and cost overruns in building projects in Indonesia. They identified the following as the critical factors: high inflation/increased material price; design change by client; defective design; weather conditions; delayed payment on contracts and defective construction work.

14 23 Koushki et al (2005) determined the time-delays and cost-increases associated with the construction of private residential projects in the State of Kuwait. The three main causes of delays are changing overruns, the three main causes are contractor-related problems, materialminimization of time delays and cost overruns would require availability of adequate funds, allocation of sufficient time and money at the design phase, and selection of a competent consultants and a reliable contractor to carry out the work. Faridi & El-Sayegh (2006) reported that over 50 percent of construction projects experience delay due to factors such as delay in approval of construction drawings, poor pre-planning and slow decision making process. Comparing the key factors of construction delay across UAE, the Kingdom of Saudi Arabia (KSA) and Lebanon, the research asserted that delay in approval, owner's slow decision making and material shortages are common causes of construction delay across the region. Other high ranked factors in UAE had no significant impact in KSA construction projects. This clearly highlights the fact that factors causing construction delay cannot be considered common across the countries. There is a need for critical analysis and validation of the factors for each country individually. Lo et al (2006) examined thirty causes of delay in Hong Kong construction projects grouped under seven categories namely client related, engineer related, contractor related, human behaviour related, project related, external factors and resource related. They found that the percentage agreement (PA) was seventy four percent between the owner and consultant group on the significance of the various causes. The consultant and contractor

15 24 groups held extremely different perceptions regarding the significance of various delay causes of Rank Agreement Factor (RAF) is 4.9 percent and percentage disagreement (PD) is 32 percent. Assaf & Al-Hejji (2006) identified that the most common cause out of the listed 73 causes of delay under nine groups in Saudi Arabian construction projects. They examined that change of orders is common factors by all parties of construction by using frequency index (FI), severity index (SI) and important index (Imp.I). According to survey results, 76 percent of the contractors and 56 percent of the consultants indicated that average of schedule delay is between 10 percent and 30 percent of the original duration. They identified that main causes between two parties such as delay in progress payments, ineffective planning and scheduling by contractor, poor site management and supervision by contractor, shortage of labour and difficulties in financing by contractor and also identified that the least important causes following change in government regulations, traffic control and restriction at site, effect of social and cultural factors and accident during construction. They found the highest degree of agreement is 72.4 percent tion coefficient method. Surveys concluded that 70 percent of projects experienced schedule delay and found that 45 out of 76 projects considered were delayed. Alghbari et al (2007) examined the factors that cause delay in construction projects in Malaysia. They reported that the factors causing delay are lack of materials on the market; lack of equipment and tools on the market; poor weather conditions; poor site conditions (location, ground, etc.); poor economic conditions (cash inflow and outflow, etc.); changes in laws and regulations; transportation delays; and external work due to public

16 25 agencies. The main finding of the study is that the financial factor is the most influencing factor in causing delay in construction projects in Malaysia. Coordination problems are considered the second important factor causing delay in construction projects, followed by materials problems. Sambasivan & Soon (2007) reviewed an integrated approach and attempted to analyze the impact of specific causes and specific effects of delays in Malaysian construction projects. They identified 10 important factors out of 28 listed factors and six main effects of delays using relative importance index. The important factors identified are contractor improper planning, contractor poor site management, inadequate contractor experience, inadequate client finance and payment for completed works, problem with subcontractor, shortage in materials, labour supply, equipment availability and failure, lack of communication between parties and mistakes during construction stage. El-Razek et al (2008) identified main causes of delays in Egyptian construction projects. They concluded that different construction parties of construction do not agree on the relative importance of various factors of delay, monthly blaming each other of delays using importance index and spearman rank correlation. They also identified the importance of team effort in the success of a project. Al-Kharashi & Skitmore (2009) identified the frequency, extent, and causes of delay of private as well as public construction projects in Saudi Arabia. They highlighted the chronic nature of the problem and disparity in the views of the project stakeholders. They found that the most influencing current cause of delay is the lack of qualified and experienced personnel attributed to the considerable amount of large, innovative, construction projects and associated current undersupply of manpower in the industry.

17 26 Olawale & Sun (2010) reported a study conducted in UK to determine inhibiting factors and mitigating measures in practice relating to time and cost overruns on construction projects in the country. The common factors that inhibit both time and cost control during construction projects were identified. Subsequently 90 mitigating measures have been developed for the top five leading inhibiting factors-design changes, risks/uncertainties, inaccurate evaluation of project time/duration, complexities and nonperformance of subcontractors. These mitigating measures were classified as: preventive, predictive, corrective and organizational measures. Doloi et al (2011) studied factors affecting delays in Indian construction projects. They identified the key factors impacting delay in Indian construction industry and established the relationship between the critical attributes for developing prediction models for assessing the impacts of these factors on delay. Factor analysis and regression modeling were used to examine the significance of the delay factors. From the factor analysis, most critical factors of construction delay were identified as lack of commitment, inefficient site management, poor site coordination, improper planning, lack of clarity in project scope, lack of communication and substandard contract. Regression model indicates slow decision from owner, poor labour productivity, architects' reluctance for change and rework due to mistakes in construction are the reasons that affect the overall delay of the project significantly. These findings are expected to be significant contributions to Indian construction industry in controlling the Time overrun in construction contracts. The major causes of delay reported by researchers from different countries are summarized in Table 2.1.

18 27 Table 2.1 Influential factors causing Time overrun in Construction Projects Researchers Country Major causes of delay Baldwin et al (1971) United States - Inclement weather - Shortages of labour supply - Subcontracting system - Shortages of resources - Financial difficulties faced by public Arditi et al (1985) Turkey agencies and contractors - Organizational deficiencies - Delays in design work - Frequent changes in orders/design - Considerable additional work Okpala Aniekwu (1988) and Nigeria - Shortages of materials - Failure to pay for completed work - Poor contract management Dlakwa and Culpin (1990) Semple et al (1994) Assaf et al (1995) Nigeria Canada Saudi Arabia - Delays in payment by agencies to contractors - Fluctuations in materials, labour and plant costs - increases in the scope of the work - inclement weather - restricted access - Slow preparation and approval of shop drawings - Delays in payments to contractors - Changes in design/design error - Shortages of labour supply - Poor workmanship

19 28 Table 2.1 (Continued) Researchers Country Major causes of delay Lo et al (2006) Hong Kong - Inadequate resources - Unforeseen ground conditions - Exceptionally low bids - Inexperienced contractor - Work in conflict with existing utilities - Poor site management and supervision - Unrealistic contract duration Faridi and El- Sayegh (2006) UAE - Slow preparation and approval of drawings - Inadequate early planning of the project - Slowness - Shortage of manpower - Poor site management and supervision - Low productivity of manpower 2.5 RESOURCE CONSTRAINT FACTORS CAUSING TIME OVERRUN One of the main problems due to which the Indian construction industries suffer is resource constraints. The factors related to resource constraints causing time overrun in construction projects is grouped under four heads such as materials related, manpower related, equipment related and finance related.

20 Material Related Factors Several studies were carried out to identify the material related factors causing delays. Abd-Majid & McCaffer (1998) identified the following factors that contribute to causes of delays: shortage of material, poor quality of material, poor procurement of material, late delivery of material, and unreliable suppliers. Chan & Kumaraswamy (1996) revealed that factors such as shortage of material and poor procurement of material are the contributors to causes of delays. Ogunlana et al (1996) reported that the factors such as shortage of material, poor quality of material, escalation of material prices and late delivery were the factors to cause delays in construction projects. Odeh & Bataineh (2002) identified that the factor, poor quality of materials has high influence on causes of delays. Koushki et al (2005) revealed that the factors such as, shortage of construction material, poor quality of material, and poor procurement of material contribute to causes of delays. Frimpong et al (2003) identified that the factor, poor procurement of materials contributed to causes of delays. Wiguna & Scoot (2005) identified the factor, escalation of material prices as one factor that contributes to causes of delays. From the literature review, ten material related factors causing time overrun were identified and are presented in Table 2.2.

21 30 Table 2.2 Material related factors causing time overrun Group Material related Factors Shortage of construction materials Materials selection and changes in types and specifications during construction. Slow delivery of materials Poor quality of materials Damage of materials in storage Damage of sorted materials while they are needed urgently Poor procurement of materials Proportion of offsite prefabrication Imported, Ordered materials and plant items. Manufacturing difficulties of special materials Manpower Related Factors Abd Majid & McCaffer (1998) identified that the factors such as slow mobilization of labour, labour supply, absenteeism, strike, and low motivation and morale are the critical factors that contribute to causes of delays. Odeh & Bataineh (2002) in their research identified the factors such as labour of productivity and labour supply as contributors to causes of delays. Chan & Kumaraswamy (1996) identified that shortage of skilled labour is the most important factor that contributes to causes of delays. Ogunlana et al (1996) identified the factors such as shortage of skilled labor and labour productivity has high influence on causes of delays.

22 31 From the above literatures, eleven manpower related factors causing time overrun were identified and are presented in Table 2.3. Table 2.3 Manpower related factors causing time overrun Group Manpower related Shortage of labour Factors Lack of skilled labour Migrant labour Labor injuries, disputes and strikes Unqualified work force team Personal conflicts among labour Obtaining permits for migrant labour Lack of motivation Lack of communication Lack of Mobilization Absenteeism of labour Equipment Related Factors Ogunlana et al (1998) reported that the factors such as insufficient numbers of equipment; frequent equipment breakdown, and equipment allocation problem are the significant factors that contribute to causes of delays. Abd Majid & McCaffer (1998) identified that the factors such as equipment breakdown, improper equipment, slow mobilization of equipment, and equipment allocation problem as the contributors of delays. Chan & Kumaraswamy (1996) reported that shortage of equipment and improper equipment are the factors contributing to causes of delays. Odeh &

23 32 Bataineh (2002) identified that equipment allocation problem is the main cause for construction delays. Long et al (2004) identified the factor of inadequate modern equipment as a factor causing time overrun of construction projects. From literature review, seven factors related to equipment causing time overrun were identified and are presented in Table 2.4. Table 2.4 Equipment related factors causing time overrun Group Equipment related Factors Availability of equipment Complication of advanced technology equipment Transportation of equipment Idle time of equipment Complication of hire Disruption of accessories Poor maintenance of equipment Idle time of equipment Finance Related Factors Abd Majid & McCaffer (1998) identified that the factors such as inadequate fund allocation and delay payment to subcontractor/suppliers as the contributors to causes of delays in construction project. Long et al (2004) reported that the high interest rate as a factor causing delays. high influence on the causes of delays.

24 33 Chan & Kumaraswamy (1996) reported that the factors such as yment difficulties as contributors to causes of delays. Koushki et al (2005) revealed that the unreasonable constraints to client have high influence on delay. Frimpong et al (2003) identified that monthly payment difficulties is the most important factor that contribute to delay. From literature review, five finance related factors causing time overrun were identified and are presented in Table 2.5. Table 2.5 Finance related factors causing time overrun Finance related Group Factors Cash Flow (Inflow and Outflow) Slab of payment during construction Financing by contractor during construction Financing between the owner and contractor Unavailability of financial incentive 2.6 DATA ANALYSIS Descriptive statistics namely Relative Importance Index (RII) has been used to highlight the relative importance of factors as perceived by the respondents. The indices were then used to determine the rank of each factor. The ranking made it possible to cross compare the relative importance of the factors as perceived by the groups of respondents. The weighted average for each factor for the three groups of respondents was determined and ranks were assigned to each factor representing the perception of the three groups.

25 Relative Importance Index (RII) Odeh & Battaineh (2002); Pourrostam & Ismail (2011) have used relative importance index to determine the ranking of different factors from the viewpoint of contractors and consultants. The Relative Importance Index (RII) was computed as: 5 WiX i i 1 RII (2.1) 5 X i 1 i where, i = response category index = 1,2,3,4 and 5 where, 1 = Very high, 2 = High, 3 = Medium, 4 = low and 5 = Very low. W i = the weight assigned to i th response = 1, 2, 3, 4 and 5 respectively. X i = frequency of the i th response given as percentage of the total responses for each factors. Many researchers (Kometa et al 1994; Assaf et al 1995; Faridi & El- Sayegh 2006; Iyer & Jha 2005, Kumaraswamy & Chan 1998, Abdalla et al 2002; Sambasivam & Soon 2007; Doloi et al 2011) used the relative importance index technique RII together with rank agreement factors and percentage agreement to analyze survey data, concluding that: W RII (2.2) A N where W is the weight given to each factor by respondent, A is the highest weight and N is the total number of respondents.

26 35 Aibinu & Jagboro (2002) determined the ranking of different factors from the viewpoint of owner, contractors and consultants. The Relative Importance Index (RII) was calculated for each item using Equation (2.3): 4n1 3n 2 2n 3 1n 4 0n 5 RII 4 N (2.3) where n 1 2 =number of respondents n 4 =number of 3 5=number of respondents parametric test. Nonparametric tests are also referred to as distribution free tests. These tests have the obvious advantage of not requiring the assumption of normality or the coefficient r is used to measure and compare the association between the rankings of two parties for a single cause of time overrun, while ignoring the ranking of the third party. Many researchers (Assaf et al 1995; Odeh & Battaineh 2002; Faridi & El-Sayegh 2006; Sambasivam & Soon 2007) used the formula: 1 6 d (2.4) s (n n) r 3 2 where r s is the Spearman rank correlation coefficient between two parties, d is the difference between ranks assigned to variables for each cause, and n is the number of pairs of rank.

27 Factor Analysis Factor analysis is primarily used to get greater insight among numerous correlated but seemingly unrelated characteristics into a much fewer underlying factors (Doloi 2009; Iyer & Jha 2005). The results form a firm basis for identifying the criticality of characteristics on construction impact. Many researchers from other areas including politics, sociology, economics, human machine systems, accident research, taxonomy, biology, medicine, geology, and construction management have also applied this technique (Kaming et al 1997; Chan et al 2001; Trost & Oberlender 2003; Ahadzie et al 2008). Factor analysis is performed for responses of all respondents as well as separately for owner and contractor responses. While the all response set has given some meaningful interpretations, the variables emerging in various factors under isolated response sets of contractor and owner have been found out to be jumbled and not leading to any meaningful interpretation. Hence the analysis and subsequent discussion is restricted to factor analysis of all responses. Since the factors extracted using principle component analysis are orthogonal and contain a large number of overlapping attributes across various factors it is not amenable to understand. So oblique rotation using varimax rotation is employed. 2.7 INFERENCE FROM THE LITERATURE Time overrun causes severe negative effect to the organization in terms of schedule, cost and quality. From the extensive literature study, it was found that studies related to time overrun were carried out mostly in foreign countries only, except the one (Doloi et al 2011) from India. From the study

28 37 it is clear that, in construction industry, the organizations do not follow any effective time overrun strategies. Nowadays, all construction projects are facing resource demands. One of the important reasons of time overrun in construction projects is resource constraints. A resource constraint strategy should be formulated and implemented efficiently to avoid time overrun. The various research works related to time overrun were studied. The literatures related to resource constraints causing time overrun of construction projects have been reviewed. The factors that cause time overrun are identified, and the factors which are appropriate, are used for the questionnaire formation. Out of the seventy five factors which influence time overrun, thirty three factors were identified as the resource related factors causing time overrun in construction projects. These thirty three resource constraint factors are grouped under four heads and are shown in Table 2.6. Table 2.6 List of factors identified and grouped under four heads Group Man Power Factors Shortage of labour Lack of skilled labour Migrant labourers Labor injuries, disputes and strikes Unqualified work force team Personal conflicts among labour Obtaining permits for migrant labour Motivation Communication Mobilization Absenteeism of labour Unavailability of financial incentive

29 38 Table 2.6 (Continued) Group Equipment Materials Financing Availability of equipment Factors Complication of advanced technology equipment Transportation of equipment Idle time of equipment Complication of hire Disruption of accessories Poor maintenance of equipment Shortage in construction materials Materials selection and changes in types and specifications during construction Slow delivery of materials Poor quality of materials Damage of materials in storage Damage of sorted materials while they are needed urgently Poor procurement of materials Proportion of offsite prefabrication Imported, Ordered materials and plant items Manufacturing difficulties of special materials Cash Flow (Inflow & Outflow) Slab of payment during construction Financing by contractor during construction Financing between the owner and contractor Unavailability of financial incentive