The term effort refers to the specific and quantifiable count and/or measure of definable labor units that it is deemed are to be required in the attempts to arrive at completion of a phase (or of the entirety) of a particular schedule activity and/or work breakdown structure component, a distinct control account, or the project as a whole. Effort, when being accounted for and quantified in a time and labor budgetary attempt is customarily presented in terms that include but are not particularly limited to staff hours, staff minutes, staff days, staff weeks, staff months, or, for particularly long projects, even staff years. A helpful way to view the definition of effort would be to directly contrast the term effort with the term duration. Effort can be measured in terms of individuals or in terms of the team as a whole and anticipated effort can ultimately be measured compared to the ultimate efforts expended.
This term is defined in the 3rd and the 4th edition of the PMBOK.
