They represent a risk to the success of the project and before you delegate a single task, you want to have an idea of the amount of work that each individual can handle.
In this paper and speech, presented at the Project Management Institute of the Southern Caribbean Chapter, I addressed this question using recent research from Brigitt Claessens. On this page with the materials from the conference, I share the audio, slides and research paper I presented.
It was a great experience presenting to an audience that takes the topic of time management so very seriously.
If you are interested in discussing the topic further, simply visit the forums at my book’s website: simply visit the newly created forums focused on Project Managment at my book’s website.