Submitted on: 27 June 2006.
Revised on: 17 August 2006.
Accepted on: 12 September 2006.
___________________Engineering Management Journal
Submitted on: 13 May 2005.
Revised on: 15 July 2005.
Accepted on: 10 August 2005.
___________________Engineering Management Journal
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Submitted on: 17 December 2006.
Revised on: 16 March 2007.
Accepted on: 12 May 2007.
___________________Engineering Management Journal
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