In this paper a new class of Non-Transferable Utility (NTU) games is introduced. We associate an NTU game to the PERT problem that arises from a method of operations research called Project Evaluation and Review Technique (PERT). The goal is to divide the slacks of time among the different activities involved in the project. We model this problem as an NTU game and we study some properties. It is shown that this class of NTU games has a non-empty core. Moreover, an easy expression for the compromise value is attained and an adjusted compromise value is defined.