The introduction of the Project Evaluation and Review Technique (PERT) dates back to the 1960's and has found wide application since then in the planning of construction projects. Difficulties with the interpretation of the parameters of the beta distribution let Malcolm et al. [1] to suggest the classical expressions for the PERT mean and variance for activity completion that follow from lower and upper bound estimates a and b and a most likely estimate θ thereof. The parameters of the beta distribution are next estimated via the method of moments technique. Despite more recent papers still questioning the PERT mean and variance approach, their use is still prevalent in operations research and industrial engineering text books that discuss these methods. In this paper an overview is presented of some alternative approaches that have been suggested, including a recent approach that allows for a direct model range estimation combined with an indirect elicitation of bound and tail parameters of generalized trapezoidal uniform distributions describing activity uncertainty. Utilizing an illustrative Monte Carlo analysis for the completion time of an 18 node activity network, we shall demonstrate a difference between project completion times that could result when requiring experts to specify a single most likely estimate rather than allowing for a modal range specification.