Use case
Return the completion percentage of an issue based on the status it is in.
Expression
Create and configure a Smart field using this expression in General parsing mode:
%{%{issue.status} = "Open" ? 0 : ( %{issue.status} = "Planning" ? 0.15 : ( %{issue.status} = "In Progress" ? 0.6 : ( %{issue.status} = "In Review" ? 0.7 : ( %{issue.status} = "Implementing" ? 0.85 : 1 ))))}
Please, replace the status names as well as the completion percentages with the ones of your choice. Any status not included in the sequence will return 1.