Overview
Effort can be enabled within the features tab and configured within the mapping tab. With effort enabled you are able to assign the amount of effort required in hours, days, week, etc. The effort and effort unit can be customized.
For an example see: effort
Implementation
Enabling effort can be done through the features tab, navigate to mapping and configure Effort and Effort unit. Effort can be a decimal, integer or long attribute, effort unit can be a string attribute (so also a enumeration). Look up ENUM_TimeUnit for possible values.