IGLC.net EXPORT DATE: 28 March 2024 @CONFERENCE{O'Brien1997, author={O'Brien, W.J. and Fischer, M.A. and Akinci, B.H. }, editor={Tucker, Selwyn N. }, title={Importance of Site Conditions and Capacity Allocation for Construction Cost and Performance: A Case Study }, journal={5th Annual Conference of the International Group for Lean Construction}, booktitle={5th Annual Conference of the International Group for Lean Construction}, year={1997}, pages={77-90}, url={http://www.iglc.net/papers/details/30}, affiliation={ Ph.D. student, Department of Civil Engineering, Stanford University ; Assistant Professor, Department of Civil Engineering, Stanford University ; Ph.D. student, Department of Civil Engineering, Stanford University }, abstract={Traditional construction thinking that an ‘optimal’ solution to the problem of shifting project schedules can be found via a time-cost tradeoff analysis does not take into account the influence of capacity allocation and site conditions on cost and performance. Specifically, the time-cost tradeoff can only account for the direct costs of compressing an activity's duration, not its capacity costs. Loosely restated, the time-cost tradeoff accounts for the costs of a change in an activity's duration but not the costs of a change of when in time the activity takes place (which will affect a firm's commitments to other projects and hence cause capacity costs). Similarly, moving an activity in time may place the activity in a different set of site conditions than those which were assumed when the activity's cost-time curve was generated. The cost-time curve of an activity may change as site conditions change, which can only be accounted for in the time-cost tradeoff optimization method by manually generating new cost-time curves for each instance of site conditions and solving anew (an exercise that quickly becomes too cumbersome to perform). This paper presents an in-depth case study of a £100 Million project highlighting the limited applicability of the time-cost tradeoff approach to real world situations and discusses the impact of site conditions and capacity allocations on cost and performance. }, author_keywords={time-cost tradeoff, capacity allocation, site conditions, supply chain management, construction scheduling }, address={Gold Coast, Australia }, issn={ }, publisher={ }, language={English}, document_type={Conference Paper}, source={IGLC}, }