Abstract:
Variation orders (VOs) are one of the main challenges that face all
building projects stakeholders. From some preliminary investigation
conducted with some construction managers in Sudan, VOs were viewed
as the main cause of increase in contract value by more than 25%,
extension of time and decrease in quality and productivity on building
projects in Khartoum state.
This research sought to identify and rank the key factors that cause VOs
gauging their impact on the time, cost and overall performance of building
projects in Khartoum State – Sudan .It also focused on valuing how
adjustment and control of VOs could be achieved. Moreover the research
aimed at developing a model to allow users to assess and later control the
impact of VOs on the project time and cost performance.
The research was conducted in three main stages: (case studies
questionnaire surveys and a model development). 10 projects were studied
thoroughly collecting information to determine the effect of VOs and this
was then complemented by an industry survey, where 130 participants took
part in a stratified sample comprising (47) consultants, (53) contractors,
(23) projects owner and (7) experienced project managers. The data was
analyzed calculating, frequency of occurrence, relative importance index,
correlation coefficient (R2) and Spearman coefficient. It was evident that a
substantial majority (70%) of the recorded causes for VOs were related to
(client‟s changing needs, client‟s changing scope of work, design changes,
instability of prices of material in local Market, Changing government
regulations and legislation and Change the use of the project) .The results
also confirmed a direct relationship between the presence of VOs and
project‟s time overrun. It was also recorded that project‟s durations
increased by (22-200) % due to VO. Cost analysis, on the other hand
showed an increase by (2.67-42.86) % due to VOs.
