Letter to the Editor—Comments on a Paper by Thomas Healy

In the May–June issue of Operations Research, Thomas Healy presents findings which he uses to demonstrate that a prescribed subdivision of activities will change probabilities in a PERT network analysis [“Activity Subdivision and PERT Probability Statements,” 9 341–347 (1961)]. As a member of the original PERT team, I would like to call attention to and take issue with some aspects of his paper.