Causes And Effects Of Design Variation In Road Construction Projects

Causes And Effects Of Design Variation In Road Construction Projects

Abstract

Variation is one of the most severe problems in the construction assiduity. This variation occurs in every construction design and the magnitude of these variations varies vastly from design to design. As similar, the customer had to spend further than what was originally estimated in utmost cases, occasionally, controversies and gratuitous detainments do due to variations. This study concentrated to probe causes and goods of design variation in road construction design in Akwa Ibom State. The objects were to examine the causes of design variation, to probe the goods of design variation in road construction systems and examine measures to minimizing its circumstance. Applicable literature review on causes and goods of design variation in road construction systems were carried out and an elaborate field check was accepted to corroborate the objects of this study. A aggregate of 62 questionnaires were collected against 68 questionnaires distributed among professionals in the construction assiduity, representing 91 response rate. The data collected through a structured questionnaire administered to the professionals were analysed using simple arbitrary slice fashion. The results revealed that change in customer’s opinions was the most predominant cause of variation. Others are adviser and contractors ’ factors were also seen as the severe causes. The results also revealed that the most common goods of design variation on construction systems were increase in design cost, detainments in completion and controversies among stakeholders. The study refocused early commerce between the design platoon and the customer to insure that customer’s conditions are clarified and communicated effectively into the design to reduce variations. The study recommends platoon work spirit amongst stakeholders involved in the design and respect to original design by the customer as the crucial constituents for a successful design delivery.

Chapter One

Preface

Background of the Study

The complexity of the construction assiduity due to different stakeholders ’ involvement makes it differ from other diligence. This complexity leads to unwanted situations like variations with their associated goods. And presently, it’s nearly getting a rare thing for a construction design not to have variation. utmost contracts these days must make vittles for possible variations given the nature of road construction design( Finsen etal., 1999).( Uff, 2005) farther refocused out that a clause permitting variation of workshop is an essential point of any construction contract because without it the contractor isn’t bound to execute fresh work or to make deletions or changes. In line with these, the nature and approach to the generality, planning and posterior fruition of construction systems are dynamic, complex, sophisticated and capital ferocious in recent times. In consequence, these systems are subordinated to acceptable appraisals by the guarantors on the base of political, social, systems cousins ’ benefits, externalities, etcetera, with a view of catching on the values of plutocrat( Onwusoye, 2005). The instrument for the consummation of this expostulation through colorful ways and other inferred factors by the implicit proprietor of the systems leads to the eventual take out of a construction design. thus, design variation need to be critically addressed as this continue to be a frequent problem that gets worse frequently in construction design. Though of recent, it’s a common miracle for design variation to do on construction design. But under normal circumstance, it’s possible for a complex set of delineations and specification to be available for medication of completely described and accurate bill of amounts for extending purposes. These would deplete farther charges as a result of design changes during the construction stage.

According to theJ.C.T. 80, design variation in road construction refers to a change in the workshop initiated by the masterminds, advisers , employer or other factors as the case may be which involves the revision of any kind or standard of accoutrements to be used in the work. A design change is regarded as any change in the design or construction of a design after the contract is awarded and inked, and similar changes are related not only to matters in agreement 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, elision or adaptation to the contract price or contract time, and it occurs regularly on construction systems. Park( 2002) defined design variation as a change to the work state, processes or styles that differ from the original construction plan or specification and generally redounded from different in work quality and condition, compass changes or misgivings that make construction dynamic and unstable. Affirmed that design variations are ineluctable on major construction systems particularly on road construction where the design is complex, the ground conditions variables or the employer desire to incorporate the rearmost technology into the design. And the further design changes on a design, the lesser effect which come time consuming and expensive in construction systems( Mohamed, 2001). It’s thus of lesser concern regarding the adverse goods 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 design redounded into a substantial proliferation in quantum of backing calculated for the work, hence caused the incapability to complete and handover the work as agreed originally at the inception of the work. As a result of this, it’s extremely conspicuous that time and cost overrun occurs due to variation in numerous construction systems especially road construction. also, variation order which contains a set of instructions that allows changes or variations 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 still do after the award of the original contract or after work might have commenced at the construction spots. The changes may be due to colorful reasons similar as the revision of original design and compass, schedule, costs and styles.

Variation from the original design design is seen as the major causes of design failure, though design monitoring and control could beget corrective conduct to bring divagation during construction but failed to take cognizance of relating and assaying the root cause of similar variation( Ubani, Nwanchukwu and Nwukonkwo, 2010). The performance objects disfigurement due to variation of numerous completed and ongoing road systems redounded in employer’s dissatisfaction, design time extension and cost overrun, low quality and unacceptable labors, design clashing between the contractors and employers arising from variation in contract sum. And the unusual thing about it’s the extent of similar differences as well as the frequence circumstance. The causes and cost recrimination of variation needs to be assessed and analysed at the onset of the design, and it’s on this background that the study was carried out.

Statement of the Problem

All road construction systems suffer colorful degrees of design variations throughout the design life cycle. Changes in construction systems are ineluctable particularly when the factual work commences to correct or modify original design or compass of work( Alnuaimi etal., 2010). The exploration study by Naoum( 1997) stressed the lack of time and effective communication, lack of integration, query, a changing terrain and adding design complexity as the motorists of design changes.

According to a study by Ogunlana, Promkuntong and Jearkjirm( 2000), construction possessors are the major causes of design variations due to changing plans in line with the changing profitable climate to meet client demands or for making marketing reasons. Design variation need to be constantly covered to avoid escalation( Olawale and Sun, 2010).