Construction delay: a quantitative analysis
Introduction
A vital section specified in the construction contract is the performance period or time of project execution, which is established prior to bidding. The successful execution of construction projects and keeping them within estimated cost and the prescribed schedules depend on a methodology that requires sound engineering judgment.[1] The construction sector is one of the vital sectors in the development process of Jordan. The government contributes to the development of the construction industry in several ways. However, there are limitations and even draw backs to these efforts. The time required to complete construction of public projects is frequently greater than the time specified in the contract. These `overruns' or time extensions are granted for many reasons, such as designer changes or errors, user changes, weather and late deliveries. Current construction projects are complex efforts requiring the support of the design and construction profession. Therefore, a realistic time for project execution will decrease the possibility of disputes between state agency and the contractors.
A great deal of information concerned with project delay and overruns may be found in the literature. The increased interest in construction overruns is due, in part, to efforts by the government to reduce construction delays. There has been a considerable and continued interest in the effect of construction delays. The information available is diverse and widespread. Many construction management books[2], [3], [4], [5], [6] have minimum coverage on construction delays. Al-Momani[7] describe the various elements of cost upon individual public projects but does not deal specifically with construction delays.
Assaf and Al-khalil[8] outline the main causes of delay in large building projects and their relative importance. They found that 56 causes of delay exist in Saudi construction projects. According to the contractors surveyed the most important delay factors were preparation and approval of shop drawings, delays in contractor's progress, payment by owners and design changes. The architects and engineers view were cash problems during construction, the relationship between subcontractors and the slow decision making process of the owner. The owners agree that the design errors, labor shortages and inadequate labor skills are important delay factors. Hancher and Rowings,[1] for example, provide a concise summary of the methodologies used by transportation agencies to establish the contract duration used for highway construction projects, and also provides a schedule guide for field engineers during construction. Similarly, Chalabi and Camp[10] conducted a review on project delays in developing countries during planning and construction stages. In their study they found that the delay and cost overruns of construction projects are dependent entirely on the very early stages of the project. Fereig and Qaddumi[11] in their study on the construction experience of the Arabian Gulf demonstrate the various components of the planning, controlling and productivity on construction delay. Their primary purpose is to alert the reader to the deviation from the project plans.
Wilson[9] examined the role of the owner and architect/engineer's roles in the prevention and resolution of construction claims. Wilson also summarised the causes of construction claims which include: extra work, project delays and acceleration, lack of management, limited site access and change in work schedule.
Despite the necessity for such research, little work has been described in the literature concerning public projects, specially in Jordan. The previously proposed factors contributing to construction delay were frequently observed in public projects. The actual frequency and magnitude of these factors is not known, which has proven to be a serious and very expensive problem to Jordan's construction industry.
The objective of this study is to determine the causes and the level of time extension of public projects and to aid construction managers in establishing adequate evaluation prior to the contract award using quantitative data. The key task is to design research so that the information obtained permits the assessment of their impact. Therefore, the best approach to assessing these potentials is to adopt randomly selected samples. The sampling population was established by selecting 130 public projects constructed in different regions of Jordan during the period of 1990–97. The data was found in contract files of several state agencies. Data collected were of 5 kinds of public projects: residential houses of public figures, office and administrative buildings, school buildings, medical centers and communication facilities. The performance and construction of these projects were recognised as being unsatisfactory to many officials, and assented to the study in order to have hard evidence as to the nature of the problems. This study will summarise the results of this research based on actual construction times experienced by public projects. The data collection was to investigate the reasons related to construction delay and overruns:
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Planned duration of contract;
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Actual completion date;
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Design changes;
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Disputes;
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Notification of extra work;
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Date of notice to proceed;
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Delay encountered during construction;
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Conflict of the drawings and specifications;
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Time extensions;
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Late delivery of materials and equipment.
Section snippets
Discussions
The data were entered into Excel 5 where all analysis and diagrams were developed. The first step was to explore the parameters as to causes of delay. To this effect, parameters were defined and constructed in Table 1 for public projects. These restrictions create a sample with 130 projects. The table provide frequencies for each parameter in five different construction categories. Many projects were delayed for many reasons. All extensions to the planned schedule were considered as delays. The
Tests and results
Simple linear regression develops an equation that describes the relationship between two variables. In this case the equation takes the form of:
In this model Y is the dependent variable, the parameters, β0 and β1 are the coefficients which are unknown and are to be estimated. X is the independent variable, and ε is a random error which is the amount of variation in Y not accounted for by the linear relationship. The theoretical models are derived and explained in the following.
For a
Limitation and suggestion for further research
While this study is among the first to provide a full test of cause and determinants of construction delay, it is not without limitations. Several shortcomings in the data can be identified such as the actual cost of construction and construction experience of the contractors. The inclusion of the construction experience of the contractors as a predictor within the model underlines the importance of this extension of the analysis into the internal information of the firms. But this factor can
Conclusion
Construction delay and overrun is a critical function in construction of public projects. It has been of great interest to construction researchers but has not been well understood in the case of public building projects. A survey of 130 projects indicated that poor design and negligence of the owner, change orders, weather condition, site condition, late delivery, economic conditions, and increase in quantities are the main causes of delay. In line with the reviewed research, the present
Dr. Ayman H. Al-Momani is an associate professor of civil engineering at Mu'tah University, Jordan. He is also vice dean of engineering and head of chemical engineering department. He served as a chairman and head of the civil engineering department for many years, and he is in charge of the construction engineering and management program, where he contributed to and developed postgraduate and undergraduate courses in construction management. He has written widely in the field and taught
References (11)
- et al.
Setting highway construction contract duration
Journal of the Construction Division, ASCE
(1981) - et al.
Professional Construction Management
(1992) - et al.
Construction Management
(1980) - et al.
Modern Construction Management
(1995) - et al.
Management Techniques Applied to Construction Industry
(1996)
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Dr. Ayman H. Al-Momani is an associate professor of civil engineering at Mu'tah University, Jordan. He is also vice dean of engineering and head of chemical engineering department. He served as a chairman and head of the civil engineering department for many years, and he is in charge of the construction engineering and management program, where he contributed to and developed postgraduate and undergraduate courses in construction management. He has written widely in the field and taught courses at Mu'tah University, University of Jordan, and University of Applied sciences in construction planning and scheduling, construction cost estimating, construction management, construction methods and equipment, quality control in construction, engineering economy and operation research. He received a BS in civil engineering from Leningrad university, MS in construction management from Oklahoma University, MS in industrial engineering from Central State University, and a Ph.D. from Oklahoma State University, USA. He is a member of national and international associations.