Evolving Concepts: Expanding Project Resources 
It is generally true that as large technical training and documentation projects evolve they place new and greater demands on existing resources. Although the intensity of the demand varies, it can usually be attributed to changes in the software application, to the addition of new learner groups, to the compression of existing schedules, and to the need for new training and documentation solutions. As projects become more demanding, resource allocation challenges become more sophisticated. Managers who bring big projects in within budget and on time, do so became they are able to allocate resources in creative, efficient, and effective ways.
Johanningsmeier, Kathleen A. STC Proceedings (1994). Articles>Documentation>Planning