The LP/IP hybrid method for construction time-cost trade-off analysis
- 1 May 1996
- journal article
- research article
- Published by Taylor & Francis in Construction Management and Economics
- Vol. 14 (3) , 265-276
- https://doi.org/10.1080/014461996373511
Abstract
Construction planners face the decisions of selecting appropriate resources, including crew sizes, equipment, methods and technologies, to perform the tasks of a construction project. In general, there is a trade-off between time and cost to complete a task - the less expensive the resources, the longer it takes. Using Critical Path Method (CPM) techniques, the overall project cost can be reduced by using less expensive resources for non-critical activities without impacting the duration. Furthermore, planners need to adjust the resource selections to shorten or lengthen the project duration. Finding the optimal decisions is difficult and time-consuming considering the numbers of permutations involved. For example, a CPM network with only eight activities, each with two options, will have 28 alternatives. For large problems, exhaustive enumeration is not economically feasible even with very fast computers. This paper presents a new algorithm using linear and integer programming to obtain optimal resource selections efficiently that optimize time/cost of a construction project.Keywords
This publication has 7 references indexed in Scilit:
- Schedule compression using the direct stiffness methodCanadian Journal of Civil Engineering, 1993
- Time‐Cost Trade‐Off Among Related ActivitiesJournal of Construction Engineering and Management, 1989
- A Dynamic Programming Solution to Cost-Time Tradeoff for CPMManagement Science, 1975
- A Horizon-Varying, Zero-One Approach to Project SchedulingManagement Science, 1974
- A Simple CPM Time-Cost Tradeoff AlgorithmManagement Science, 1971
- A Structural Method of Computing Project Cost PolygonsManagement Science, 1963
- Critical-Path Planning and Scheduling: Mathematical BasisOperations Research, 1961