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IJSTR >> Volume 1 - Issue 4, May 2012 Edition



International Journal of Scientific & Technology Research  
International Journal of Scientific & Technology Research

Website: http://www.ijstr.org

ISSN 2277-8616



AN EFFICIENT ALGORITHM FOR CRASHING

[Full Text]

 

AUTHOR(S)

B. R. Kharde, G. J. Vikhe Patil

 

KEYWORDS

CPM, PERT, Crashing, time-cost trade-off, Least Cost Schedule, Economic Crash Limit, Unit Time Method

 

ABSTRACT

Time-Cost Trade-off in Projects (TCTP), Least-Cost Schedule (LCS) or crashing technique is used to find optimum project duration to minimize the total cost. In crashing an activities, the direct cost (DC) increases while indirect cost(IC) reduces. So it is double beneficiary technique for managers to decrease the project duration as well as total cost. The goal in crashing is to find the optimum duration or Least Cost Schedule (LCS) where the total cost of the project is least. Unit Time Method (UTM) is the powerful procedure for crashing; yields always optimum solution and is used widely for CPM networks. But much iteration (one for crashing one unit of time) are needed to get to LCS. This is a disadvantage of UTM if project is to be crashed for double figure or more time. Say project crashing for 30 days 30 iterations! Other short cuts avoiding UTM are error porn and errors are observed in few cases (literature). We propose new algorithm which works on UCM logic but requires less iteration. In some problems iterations are reduced to just number of activities crashed till LCS. Algorithm can be viewed as modified Unit Time Method; would always yield the optimum in very less iterations (10 to 30% approximately).

 

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