Effort is a uniform span of time for measuring work on your product. Defining the unit of effort is an essential part of planning your work.
TeamForge 8.0 shows you the effort that has been estimated, and actually expended, for each artifact on the tracker summary screen. Parent artifacts can automatically add up these effort figures from their child artifacts’ effort figures. The calculator icon indicates that the artifact’s effort is a sum of its child artifacts’ effort within the project. When the effort from children artifacts in projects across the TeamForge (foreign children) is included in calculations, the icon, appears.
The unit of effort should be something that makes sense in your environment. TeamForge does not require any particular unit. Your unit of effort might be hours per person, days, weeks, or something else. (If you are using a scrum-based project methodology, you may have opted to measure effort in relative terms, using points (story points), in which case you can leave the Effort fields blank.)
For example, some teams use the "ideal hour" as their standard unit of effort. To define an ideal hour, consider all the activities in a standard work day that must be done but don't directly contribute to development: installing and configuring tools, eating lunch, responding to email and instant messages, providing customer support, etc. For every hour of direct development work, how much time goes into these activities, on the average? If the answer is about a half hour, then your ideal hour is 1.5 clock hours.
Now consider a task that you judge to represent about four hours of direct development work. The value you'll enter in the Effort field is 6, because for each hour of direct development you'll need an extra half hour to make that development work possible.
In an environment with a lot of overhead -- for example, a group that relies on a very complex tool set -- your ideal hour might equal two clock hours, or perhaps much more. This is not in itself a problem: the point is not to suppress needed activities, but to plan realistically, in order to reduce the need for routine scheduling adjustments and to forecast more reliably.
(However, when units of effort seem radically out of line with reality, this may be a clue that something in the environment could be better optimized.)