The secondary impact of variation orders : a qualitative analysis

[摘要] ENGLISH ABSTRACT: Variations made to the original scope of works are part of construction projects. Varying the scope of works has a cost and time impact, also referred to as the direct impact of V.Os. The direct impact is generally well understood by both contractor and client. Over and beyond the direct impact, V.Os also have a secondary impact on a project. Unlike the direct impact, the secondary impact appears not to be well recognised and managed by South African contractors.The principal aim of the research is to understand the secondary impact of V.Os. Based on this understanding, it then aims to give guidelines and recommendations to assist contractors to manage the secondary impact of V.Os. A variety of methods are used in this thesis. It includes literature review, questionnaire surveys and interviews.The qualitative analysis consists out of a pre-investigation which provided insight on how contractors deal with the secondary impact of V.Os. The JBCC and the GCC were analysed, which provided an understanding on how the contract deals with V.Os and its secondary impact. A definition was developed for the secondary impact. Key terms in the definition were analysed that assist with its understanding. Through means of a detailed literature review of relevant literature, a collection of delay and disruption events were identified that could be triggered by V.O. Studies are presented that proves V.Os cause a loss of productivity on construction projects. A comprehensive and systematic overview was given that explains the secondary impact of V.Os on construction projects. The main events discussed in the overview were validated for the South African contractor through means of interviews conducted with 2 contractors and questionnaires sent out to 44 individuals.It was found that in general, some South African contractors have accepted the secondary impact as part of construction projects. Contracts do not explicitly consider the secondary impact of change, nor does it provide clear guidelines as to how it should be addressed by the parties in contract. It was concluded that the secondary impact is unforeseen loss of productivity on the unchanged work due to the synergistic effect of the disruption caused by a multitude of V.Os (Jones, 2001, Hanna, 2004 and Ibbs, 2005). The secondary impact is an impact on human factors such as morale, self-esteem, motivation and the cause of difficult working conditions. It is a disruption that prevents project activities and events from starting and ending at the planned time and also prevents contractors from executing activities as planned. The cost due to the secondary impact is a combination of increased labour cost and also the increased cost of completing the unchanged work.It is clear that to pro-actively manage the secondary impact of V.Os will require the cooperation from the contract, the contractor and the client. In short contractors will need to understand the secondary impact, be aware of and prepared for delay and disruption events, keep record of the impact, monitor and control labour productivity and maintain a good relationship with the client.

[发布机构] Stellenbosch University