A quantitative assessment of the cost and time impact of variation orders on construction projects

Purpose – Variation orders are a common occurrence in construction projects and their impacts have been studied by various authors. However, the contribution of project variations to construction cost and time overruns is yet to be established. The purpose of this study is to assess the significance of variations as a cause of cost and time overruns.Design/methodology/approach – Using a questionnaire survey, responses were obtained from 50 project participants on the causes and effects of project variations. Cost and time data were also collected on 30 completed building projects. The analysis used importance indices and F‐ and t‐tests. The results indicated that variations had a significant effect and accounted for about 79 and 68 per cent of the cost and time overruns, respectively, for the projects studied.Findings – The results indicated that variations had a significant effect on project cost and time overruns and accounted for about 79 and 68 per cent of the cost and time overruns, respectively, for...

[1]  Adeyinka A. Okuwoga.  Cost–time performance of public sector housing projects in Nigeria* , 1998 .

[2]  J. B. Newman,et al.  Construction related factors influencing the choice of concrete floor systems , 2002 .

[3]  Peter E.D. Love,et al.  Determinants of rework in building construction projects , 2004 .

[4]  John D. Sterman,et al.  System Dynamics Modeling for Project Management , 1992 .

[5]  Simon Birchall,et al.  Contract Practice for Surveyors , 2006 .

[6]  Mohan M. Kumaraswamy,et al.  An evaluation of construction time performance in the building industry , 1996 .

[7]  S. Ogunlana,et al.  Construction delays in a fast-growing economy: Comparing Thailand with other economies , 1996 .

[8]  Faisal Manzoor Arain,et al.  Strategic Management of Variation Orders for Institutional Buildings: Leveraging on Information Technology , 2005 .

[9]  Anny Nathaniel Aniekwu,et al.  The business environment of the construction industry in Nigeria , 1995 .

[10]  Glenn Ballard,et al.  Introducing a New Concept and Approach to Modeling Construction , 1997 .

[11]  C. William Ibbs,et al.  Fast-Tracking's Impact on Project Change , 1998 .

[12]  C. Loch,et al.  Contracting for major projects: eight business levers for top management , 2004 .

[13]  Awad S. Hanna,et al.  Impact of Change Orders on Small Labor-Intensive Projects , 2004 .

[14]  Edwin H.W. Chan,et al.  Dispute resolution management for international construction projects in China , 2005 .

[15]  A. A Kwakye.  Construction Project Administration in Practice , 1997 .

[16]  Mohamed A. El-Haram,et al.  Factors affecting housing maintenance cost , 2002 .

[17]  Gbenga Matthew Ayininuola,et al.  ASSESSMENT OF BUILDING FAILURES IN NIGERIA: LAGOS AND IBADAN CASE STUDY , 2005 .

[18]  P Morris.  Why Project Management doesn’t always make business sense , 1998 .

[19]  Awad S. Hanna,et al.  STATISTICAL-FUZZY APPROACH TO QUANTIFY CUMULATIVE IMPACT OF CHANGE ORDERS , 2002 .

[20]  Jeffrey S. Russell,et al.  Impact of change orders on labor efficiency for electrical construction , 1999 .

[21]  H. Randolph Thomas,et al.  Quantitative Effects of Construction Changes on Labor Productivity , 1995 .

[22]  Awad S. Hanna,et al.  Quantitative Definition of Projects Impacted by Change Orders , 2002 .

[23]  Peter E.D. Love,et al.  An Economic Analysis of the Effect of Delays on Project Costs , 2003 .