Extending project time–cost analysis by removing precedence relationships and task streaming

Non-linear time-cost trade-off models of activity crashing: Application to construction scheduling and project compression with fast-tracking

“…Surprisingly, hardly any of these later algorithms have considered crashing models which are not either linear or discrete. A few exceptions where non-linear models have been implemented include: Vrat and Kriengkrairut (1986) [11], Nonobe and Ibaraki (2006) [17], and Goh and Hall (2013) [18] who used convex piece-wise linear functions; Deckro et al (1995) [10] and Liberatore and Pollack-Johnson (2006) [19] who employed quadratic models; Khosrowshahi (1997) [15] who used cubic polynomial curves; and Diaby et al (2011) [12] who incorporated negativeexponential curves. Unfortunately, little if any evidence has been provided as to why these alternatives are superior and/or more realistic than their linear or discrete counterparts.…”

A New Innovative Cooling Law for Simulated Annealing Algorithms

“…Among the more recent approaches it is possible to cite (Tung, 2007), who develops and tests a particle swarm optimization algorithm, Aghaie and Mokhtari (2009) whose approach is based on the AC optimization metaheuristic and Monte Carlo simulation technique, Liberatore and Pollack-Johnson (2006) who propose a quadratic mixed integer programming approach for reducing the project completion time.…”

Time-cost trade-offs in resource-constraint project scheduling problems with overlapping modes

“…As assumed in Liberatore and Pollack Jonhson (2006) and Gerk and Qassim (2008), the problem is formulated in a deterministic environment. In particular, we assume that, for each couple of overlappable activities and for each overlapping mode, the total rework duration and cost, and the communication/coordination duration and cost, are constant and preliminary known.…”

“…The cost of rework is usually considered as a linear function of the rework duration with or without a fixed cost (Roemer et al, 2000;Roemer and Ahmadi, 2004;Gerk and Qassim, 2008;Lin et al, 2010). However, the models proposed in the literature for a whole project with several overlappable couples of activities consider a simplistic linear relation between the rework and the amount of overlap (Cho and Eppinger, 2005;Liberatore and Pollack Jonhson, 2006;Gerk and Qassim, 2008). Similarly, Lin et al (2010) assumed that the communication/coordination cost is proportional to the amount of time spent for communication/coordination.…”

“…To our knowledge, such scheduling problems with and overlapping has only been treated by Liberatore and Pollack Jonhson (2006) and Gerk and Qassim (2008). To our knowledge, such scheduling problems with and overlapping has only been treated by Liberatore and Pollack Jonhson (2006) and Gerk and Qassim (2008).…”