Statistical analysis of causes for change orders in metropolitan public works

The fragmentation of design and construction processes increases the likelihood change orders in conventional project procurement methods. According to the related literature and practical experience, the causes for change orders are greatly varied, thus making the task of change management difficult for most clients. In consequence, cost and time overruns are often the direct outcome of mismanagement of changes. This paper, however, argues that this undesirable situation can be minimized or avoided as long as a mechanism for handling change orders can be understood and built into project management. This paper reviews the recorded change orders in 90 metropolitan public work projects completed before the year 2000 in Taipei, Taiwan. Based on this database, the chains of events are identified and the causes for change orders are categorized. Statistical correlation and variance analysis are used to find the connection among layers of events or causes. This study further provides preliminary recommendations about project management for change orders. The finding of this paper can be used as a reference for clients in developing their project procurement strategy.