English
中文INTRODUCTION
The construction industry in China is of paramount importance for employment and economic growth. Therefore efforts geared towards improving construction efficiency by means of cost effectiveness and timeliness would be worthwhile and it will certainly contribute to cost savings for the country as a whole. There is worldwide accepted criterion for measuring project success. According to Dissanayaka and Kumaraswamy, (1999), time, cost, quality target and participation satisfaction have been identified as the main criteria for measuring the overall success of construction projects Ogunsemi and Jagboro (2006) assert that cost and time tend to be the most important and visible, always considered as very critical because of their direct economic implications if they are unnecessarily exceeded. However, Ifte et al (2002) opines that the estimation of time has continued to be a problem of great concern and interest to both the researchers and contractors.
Timely completion of a construction project is one goal of the client and contractor because each party tends to incur additional costs and lose potential revenues when completion is delayed (Thomas et al, 1995). In other words, project cost can be said to be a function of the completion time. The more the extension of time then there is likelihood of increased cost. Chan and Kumaraswamy (1996) opine that a project is usually regarded as successful if it is completed on time, within budget and to the level of quality standard specified by the Client at the beginning of the project. However, severe criticisms of the industry are generated when projects take far longer than planned.
It is generally known that the time and cost of a project are interrelated (Rasdorf and Abudayyeh, 1991). Time and cost overrun can best be explained as a situation whereby the duration time and estimated cost of a project exceeded. The problem of time and cost overrun is acclaimed to be worldwide. Chan and Kumaraswamy (1996) find out that seven-eights of building contracts surveyed in the 1960s were completed after scheduled completion in Australia while in Hong Kong, 70% of building projects were delayed in completion. In Saudi Arabia, Al-Khalil and Al-Ghafly (1999) affirm that contractors accepted that 37% of all their projects were subject to delay while consultants admitted that delayed projects accounted for 84% of projects under their consultancy.
RESEARCH QUESTIONS
- According to Zhang and Anita (2005) the construction industry in China has been criticized for poor performance and low effectiveness in terms of quality and profitability in the face of challenges and uncertainties resulting from the fast changing economic environment. What are the reasons for the contractors’ poor performance and low effectiveness in term of the cost and duration of construction projects in China?
- What are the economic implications of this to China continual economic growth?
- What are the causes of time and cost overrun in China?
- What are the effects of time and cost overrun on project delivery in China?
- What is the relationship between time and cost of construction?
AIM AND OBJECTIVES
The aim of the research work is the assessment of the effects of time and cost overrun on project delivery in China. The followings form the objectives of the research:
- To identify and evaluate causes of time and cost overall in China.
- To evaluate the effects of time and cost overrun on project delivery in China.
- To establish a time-cost model prediction of time and cost performance in China construction industry.
NEED FOR THE STUDY
The concept of project duration is important in assessing the success or viability of a construction project. According to Ogunsemi and Jagboro (2006) construction cost and time have always been seen as some of the benchmarks for assessing the performance of a project and the efficiency of the project organization. If time and cost are significant in measuring project success, this research work is therefore worthwhile.
Not much work is known to have been done to predict time and cost performance, and Clients are becoming uncomfortable at seeing their projects completed after longer duration. The research work is necessary in assisting the clients and contractors in their quest for value for money and making profits.
SCOPE AND LIMITATION
Since construction activities fall into different categories such as building, civil and heavy engineering among others, the study will focus on building and civil works within the public construction projects alone.
RESEARCH METHODOLOGY
For every research work to be successful and concluded logically there is need for appropriate statistical tools that are universally acceptable for such research work. Therefore, in order to be able to answer the research proposal questions, an appropriate methodology of research that can answer these specific questions of the research will be used. Specifically, the research methodology will discuss issues such as the target population, the sampling techniques and sample size, data collection procedure and method of data analysis.
THE TARGET POPULATION
This research work is targeted at the Quantity Surveyors, Architects; Engineers (Civil, Structural, Electrical and Mechanical) Contractors, Government relevant works departments and immediate users. The names of the professionals will be obtained from their respective professional bodies in China while the names and addresses of public project contractors in China will be obtained from China Government relevant agencies.
SAMPLE TECHNIQUE AND SAMPLE SIZE
It is practically impossible to collect data from all the targeted population in the study area. In view of this, the sample size formula will be used to determine the number of respondents to be selected.
This formula will assist in the determination of the size of the respondents to be sampled in each city of the study areas. The following formula will be used to determine the number of questionnaires that will be distributed in each city according to the sample size:
A stratified random sampling technique will be used in the distribution of questionnaire to the respondents within the sample size.
DATA COLLECTION AND ANALYSIS
Data collection will involve the use of questionnaire to get relevant data while time and cost data for completed projects will be obtained in the cities. Emphasis will be placed on the initial and final cost of the projects. Likewise, the estimated completion time and the actual completion time will be obtained from the Quantity Surveyors and Contractors. Data will be obtained from projects completed within the last Fifteen Years 1991-2006). During this period, the economic of China witnessed a rapid growth. Xing and Zhihui (2005) affirm that construction sector has played a key role in Chinese economy, which has been experiencing a rapid growth for the past two decades.
The data will be obtained from the major cities in China where construction is considered to be at its peak.
The costs to be obtained will be adjusted to the last year of study (2006). This is necessary because the cost data to be obtained will be based on different points in time and possibly different economic situations (Bowen, 1982). It is necessary that all measures are taken to make model to be as reliable as it is practically possible. Ogunsemi (2002) is of the opinion that making predictive model to be as accurate as possible, homogeneity of data is very important.
The data collection tools will include the use of the internet, postal services, personal visit and telephoning.
Four methods of analysis will be used in the course of this analysis. Percentile will be used to analyse background information on respondents. Mean score will be used to evaluate the causes of time and cost overrun. Factor analysis will be used in this study to reduce the identified effects of time and cost overrun to the very significant ones. This method is scientific statistical tools that produces a clear and unbiased extracted most significant factors among numerous factors. The data will undergo suitability test that involves an examination of the determinants of the correlation matrix.
This research work intends to establish a time-cost model prediction. In achieving this, regression analysis will be used. Regression analysis is a technique that finds a formula or mathematical model which best describes a set of data collected (Ashworth, 1986). There is need for the validation of the models by testing the hypothesis using t-test to establish the significant level between the predicted and observed values of the dependent variables.
The hypothesis to be tested at 5% significance level are as follows:
H0: There is no significant difference between the observed and the predicted values.
H1: There is a significant difference between the observed and the predicted values.
Where t-calculated is < t- tabulated, H0 is accepted. This implies a valid model.
Furthermore, a regression test will be carried out between the observed and predicted values. A good model ought to show a high coefficient of determination (R2) while the intercept and slope should be close to 0 and 1 respectively. The EXCEL and SPSS 10.0 Version Computer software packages will be used for the analysis of data relating to regression models.
THE ETHICS OF RESEARCH AND CONFIDENTIALITY
In the course of any research work, all ethical issues in respect of the right and privileges of the respondents are by law to be adhered to. In doing this, the respondents will be duly informed what the research is all about and what it intends to achieve. An assurance of the confidentiality of information given will be made sure to the respondents. They will be informed that the research is purely academic. The respondents consent will also be sought. The researcher is aware that he owns the respondents duty of protection and more so, at any point of time the respondents are free to withdraw from participation. The respondents are also entitled to know the outcome of the research work if so demanded.
EXPECTED CONTRIBUTION TO KNOWLEDGE
The study will contribute to the body of knowledge in the following ways:
- China construction industry will be able to measure the success so far recorded in the industry.
- All the stakeholders will be aware of the implications of time and cost overruns on project delivery.
- The clients and the contractors’ values for money and profit making scenario will be addressed.
- The implications on the China economy will be made known to Government of China and users of the projects.
