Causes And Effects Of Design Variation In Road Construction Projects

Project and Seminar Material for Quantity Surveying QS

Causes And Effects Of Design Variation In Road Construction Projects


Variation is one of the most severe problems in the construction industry. This variation occurs in every construction project and the magnitude of these variations varies considerably from project to project. As such, the client had to spend more than what was initially estimated in most cases, sometimes, disputes and unnecessary delays occur due to variations. This study focused to investigate causes and effects of design variation in road construction project in Akwa Ibom State.

The objectives were to examine the causes of design variation, to investigate the effects of design variation in road construction projects and examine measures to minimizing its occurrence. Relevant literature review on causes and effects of design variation in road construction projects were carried out and an elaborate field survey was undertaken to verify the objectives of this study. A total of 62 questionnaires were collected against 68 questionnaires distributed among professionals in the construction industry, representing 91% response rate. The data collected through a structured questionnaire administered to the professionals were analysed using simple random sampling technique.

The results revealed that change in client’s opinions was the most predominant cause of variation. Others are consultant and contractors’ factors were also seen as the severe causes. The results also revealed that the most common effects of design variation on construction projects were increase in project cost, delays in completion and disputes among stakeholders. The study pointed early interaction between the design team and the client to ensure that client’s requirements are clarified and communicated effectively into the design to reduce variations. The study recommends team work spirit amongst stakeholders involved in the project and respect to original design by the client as the key ingredients for a successful project delivery.

Chapter One


1.1 Background of the Study

The complexity of the construction industry due to different stakeholders’ involvement makes it differ from other industries. This complexity leads to unwanted situations like variations with their associated effects. And presently, it is almost becoming a rare thing for a construction project not to have variation. Most contracts these days must make provisions for possible variations given the nature of road construction project (Finsen et al., 1999). (Uff, 2005) further pointed out that a clause permitting variation of works is an essential feature of any construction contract because without it the contractor is not bound to execute additional work or to make omissions or changes.

In line with these, the nature and approach to the conception, planning and subsequent actualization of construction projects are dynamic, complex, sophisticated and capital intensive in recent times. In consequence, these projects are subjected to adequate appraisals by the sponsors on the basis of political, social, projects relatives’ benefits, externalities, etcetera, with a view of ascertaining the values of money (Onwusoye, 2005). The certification for the realization of this objection through various techniques and other implied factors by the potential owner of the projects leads to the eventual take off of a construction project.

Therefore, design variation need to be critically addressed as this continue to be a frequent problem that gets worse often in construction project. Though of recent, it is a common phenomenon for design variation to occur on construction project. But under normal circumstance, it is possible for a complex set of drawings and specification to be available for preparation of fully described and accurate bill of quantities for tendering purposes. These would deplete further charges as a result of design changes during the construction stage.

According to the J.C.T. 80, design variation in road construction refers to a change in the works initiated by the engineers, consultants, employer or other factors as the case may be which involves the alteration of any kind or standard of materials to be used in the work. A design change is regarded as any change in the design or construction of a project after the contract is awarded and signed, and such changes are related not only to matters in accordance with the provision of the contract but also changes to the work conditions. Akinsola et al (1997) also noted that these changes as any additions, omission or adjustment to the contract price or contract time, and it occurs regularly on construction projects.

Park (2002) defined design variation as a change to the work state, processes or methods that differ from the original construction plan or specification and usually resulted from different in work quality and condition, scope changes or uncertainties that make construction dynamic and unstable. Affirmed that design variations are inevitable on major construction projects particularly on road construction where the project is complex, the ground conditions variables or the employer desire to incorporate the latest technology into the project. And the more design changes on a project, the greater effect which become time consuming and costly in construction projects (Mohamed, 2001). It is therefore of greater concern regarding the adverse effects of the design changes in both public and private construction in Akwa Ibom State.

According to Arian and Pheng (2005), design variation on road construction project resulted into a substantial increment in amount of funding budgeted for the work, hence caused the inability to complete and handover the work as agreed initially at the commencement of the work. As a result of this, it is extremely noticeable that time and cost overrun occurs due to variation in many construction projects especially road construction. Similarly, variation order which contains a set of instructions that allows changes or modifications to be made to as earlier agreement in terms of volume or nature of task to be carried out, (O’Brien, 1998). These changes are however occur after the award of the initial contract or after work might have commenced at the construction sites. The changes may be due to various reasons such as the modification of original design and scope, schedule, costs and methods.

Variation from the original project design is seen as the major causes of project failure, though project monitoring and control could cause corrective actions to bring deviation during construction but failed to take cognizance of identifying and analyzing the root cause of such variation (Ubani, Nwanchukwu and Nwukonkwo, 2010). The performance objectives defect due to variation of many completed and ongoing road projects resulted in employer’s dissatisfaction, project time extension and cost overrun, low quality and substandard outputs, project conflicting between the contractors and employers arising from variation in contract sum. And the unusual thing about it is the extent of such differences as well as the frequency occurrence. The causes and cost implication of variation needs to be assessed and analysed at the onset of the project, and it is on this background that the study was carried out.

1.2 Statement of the Problem

All road construction projects undergo various degrees of design variations throughout the project life cycle. Changes in construction projects are inevitable particularly when the actual work commences to correct or modify original design or scope of work (Alnuaimi et al., 2010). The research study by Naoum (1997) highlighted the lack of time and effective communication, lack of integration, uncertainty, a changing environment and increasing project complexity as the drivers of design changes.

According to a study by Ogunlana, Promkuntong and Jearkjirm (2000), construction owners are the major causes of design variations due to changing plans in line with the changing economic climate to meet customer demands or for making marketing reasons.

1.3 Objective of the Research

The main objectives of this research study are:

  1. To identify the predominant causes of design variation prevalent in construction of roads in RIVERS STATE.
  2. To identify the main agents for the predominant causes of design variation.
  3. To investigate the potential effects of design variation in road construction projects in RIVERS STATE.
  4. To recommend how to control and minimize design variations.

1.4 Research Questions

In order to achieve a valid conclusion, the research study was guided by the following questions:

  1. What are the predominant causes of design variation in road construction projects?
  2. Which contacting party is mostly initiating the predominant causes of design variation?
  3. What are the most consequential effects of design variation in road construction .
  4. How can design variations be controlled or minimized in road construction projects?

1.5 Significance of the Study

Generally, the study is envisaged to provide valuable and relevant information for all contracting parties based on findings of the study on design variation in road construction projects In RIVERS STATE. This study will assist both employers and road contractors to identify the potential causes and effects of design variation in order to minimize and control its consequential impacts. The study will also lay a foundation for further research on the subject matter.

1.6 The Research Scope and Limitations

Despite the fact that variation orders are affecting seriously the road construction projects of Rivers state it has never been properly studied. This brings a great shortage of reference materials on the subject matter.

1.7 Brief Methodology

The study has used both primary and secondary data. The primary data for the study was obtained through distribution of questionnaires to professionals involved in the construction of the city road projects. In order to enrich the questionnaire for the research, a review of books and journals were used to identify the various efforts that have been made in the past to evaluate and examine the causes, effects and controls of variation orders on road construction projects. Simple statistical analysis involving tables, rankings and percentages were used in analyzing the results from the questionnaire. Descriptive explanations were also employed in making the analysis more meaningful. Secondary sources of data were obtained from relevant literatures that covered research and publication on the subject matter.

1.8 Limitation Of The Study

Construction of road projects in the public sector has assumed significant functions, hence the need for assessment on the causes, effects and controls of variation orders in Rivers state Road projects is therefore in order to achieve overall project objectives. Historical data related to variation order is not well recorded hence getting data for this study was very difficult. Data collection and analysis was therefore mostly limited to the data received from project supervisors, colleagues and volunteer professionals who are participating in the city road construction projects.

1.9 Research Outline

This research will have the following broad categories.

  • Chapter I: Introduction/ Research Overview
  • Chapter II: Literature review
  • Chapter III: The research design and methodology
  • Chapter IV: The research analysis and discussions
  • Chapter V: The research conclusions and recommendations

Each of the above chapters will contain the following contents as stipulated below.

Chapter I: describes the research overview, its initiation and purposes. It also indicates the research objectives, how the research process is conducted and the contents of the research.

Chapter II: covers the literature review part of the thesis; the literature review will include general information about causes, effects, origin agent and controls of variation orders.

Chapter III: covers the research methodology. The methodological approach consists of the overall research strategy; the study approach, data source and collection, method of analysis and writing of the research paper.

Chapter IV: Contains the analysis and discussion part. It contains the findings on causes and effects, origin agents and possible controls of variation orders.

Chapter V: in this part based on the findings of the study, conclusions and recommendations are presented.

Chapter Five

Conclusions and Recommendations

5.1 Conclusions

Road projects play a significant role in the economy of a country particularly in developing countries like Nigeria. Thereby, nowadays the number and complexity of city road construction projects is increasing in the capital city of Nigeria, Akwa Ibom state. However, many construction management problems are beset during construction stage. Among those, variation order is a considerable issue which this research paper is trying to address briefly. This study therefore aimed to identify main causes of variation orders, predominant origin agents to the causes, identify consequential effects and propose controls for variation orders in the national contracts of city road construction projects of Akwa Ibom state. Thus in accordance to the study objectives, a comprehensive literature review, questionnaire survey among construction professionals and desk study were conducted for national contract road construction projects of Akwa Ibom state.

Both the questionnaire survey and desk study confirmed the existence and extent of variation order in national contract road construction projects of Akwa Ibom state. The questionnaire survey indicated all of the respondents have been involved in the administration of variation orders of the city road projects. This was later reinforced by the findings of the desk study for 16 randomly selected city road projects and all projects faced variation orders ranging from 1 to 7 and average percentage increase of 24.11 % of the original project contract amount and the corresponding associated average time overrun is 126.50% of the original contract period.

The findings of the analyzed survey results have been thoroughly discussed in the previous chapter and therefore the following conclusions are drawn in accordance with the objectives of the study.

  1. The most frequent causes of variation orders in road projects of Akwa Ibom state were identified based on the ranking for the occurrence of frequency of 35 identified possible causes of variation orders from the review of the literature. The most ranked common causes of variation orders identified are Right of way (access to site) problem, change in design, errors and omissions in design, lack of coordination between contracting parties/stakeholders and change of plans or scope of the project. The result revealed that inadequate design, error and omission in design and ambiguous design were the main causes of consultant initiated variations while Right of way (access to site) problem, change of plans or scope and inadequate objectives were the main causes of client initiated variations. In agreement to the above, a study by Sunday, O.A (2010) on public construction projects indicated inadequate working drawings, design discrepancies and conflicts between contract documents are the most prevalent sources of variations due to consultants while change of plans or scope, impediment in prompt decision making and inadequate project objectives contributed mostly to variations by the owner. The findings of this thesis indicated that an involvement of the client is required at all project management stages and have proper project scope and objectives.
  2. The survey analysis indicated that consultant is the most frequently involving party as an origin agent of predominant causes of variation orders in Akwa Ibom state Road constructions projects. The client is ranked 2nd as an origin agent of variation orders. On the contrary, a thesis by Tadesse Ayalew (2009) concludes that contractors are the most common variation order initiators on Federal road projects of Nigeria. However, Arian and pheng (2005), in agreement to this study, clearly showed that consultants and clients respectively are the most predominant initiators of variations on public construction projects. The occurrence of variation orders was identified to be a consequence of the behavior of the consultant and the client during the pre-tender stage of construction. This could be the main reason that the contractor had least influence on variation orders during the construction stage of the city roads. Nevertheless, in all such cases the consultants were not held accountable rather they have got additional payments as their supervision contract is a time based contract.
  3. The most identified predominant ranked adverse effects of variation orders in Akwa Ibom state Road construction projects are cost overrun, time overrun and disputes between contracting parties in agreement to the findings of researchers Arian and pheng (2005) and Aldubaisi A.H. (2000).On the other hand, survey results also indicated that the client is the most affected party.
  4. As per the respondents’ survey data, application of proper controlling tools for work variations in Akwa Ibom state road projects is weak. As per the survey result finding, the following are the most applied three stage controlling mechanisms of variation orders during the road construction project management. Timely written approvals and owners’ involvement during construction stage were rated most. During design stage, review of contract documents and owners’ involvement at planning and design phase were rated next. Likewise, utilizing of work breakdown structure and continuous coordination and direct communication among parties were also rated most during the design-construction interface stage.

5.2 Recommendations

Recommendations forwarded from this thesis are a set of remedies to minimize variations in construction projects and minimize their impacts in future road construction projects of Akwa Ibom state. Based on the findings of this research discussed in chapter four with main conclusion listed above and the referring to findings of previous studies discussed in the literature review, the following recommendation are made:

A clear and thorough project brief by the client would assist in eliminating variations that may arise due to unclear project objectives. Eventually, this may assist in developing a clear scope of work for the professionals.

  1. The involvement of the owner/client in the design phase would assist in clarifying the project objectives and in identifying the noncompliance with their requirements at an early stage. Eventually, this may help in eliminating the occurrence of variations arising from errors and design discrepancies during the construction stage where the impact of the variations can be severe.
  2. The establishment of an independent organization, who has the authority to command and coordinate all stakeholders participating in the city road construction and infrastructure development program, is vital in order to alleviate right of way and related problems. Unless there is some organization that is capable of coordinating and guiding all stakeholders, ROW problem continue to be a dominant problem. On the other hand, an integrated design manual which includes all utility facility under walkway shall be prepared by the client for the typical sections of the city roads to be adopted by the design consultants.
  3. Another justified recommendation for the client is to review the original design by an independent design consultant to avoid most of the consultant related predominant causes of variations. In addition to this, the client need to get a project management consultant firm (PMC) to supervise both the design and construction activities to insure that the owners’ needs and expectations are met by the design. The practice of appointing PMC is rarely adopted currently.
  4. Thorough detailing of design was perceived as one of the most effective controls for variation orders for city road projects. The controls for the errors and omissions in design, design discrepancies and frequent change in design, would be minimized through detailing of design only by having staged offices that shall overlook in to designs made by juniors who are inexperienced. This will provide an opportunity for the consultant to review and finalize the design during the design phase. This would assist in reducing the variation occurrences during the construction phase where the impact of variations can be severe.
  5. As discussed in the previous sections, the most important causes of variation orders were mostly consultant related variations and client related variations respectively. Hence, the study suggested that variations can be reduced with due diligence during the design stages and project defining moments if there exist a proper channel of communication. Furthermore, the suggested controls also emphasized the proper involvement of all parties for a collaborative effort in reducing variations.
  6. The identification, analysis and documentation of potential variations in a project as early as possible can enhance the management of variations in the projects. Learning from these variations is imperative because the professionals can improve and apply their experience in the future.
  7. Finally I recommend my fellow researchers for further studies on variation order management in city road construction projects as it is proven to be a potential study area during this study process.

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