Some supported report types, Timepiece (formerly Time in Status) allows sorting the report output by the calculated report values.
If a report type supports sorting, you will see the Sort button, on the right side of the report output table.
Clicking this button will open a panel that lets you select the sort field and sort direction.
For status-based reports that support sorting, if no statuses are selected in Status panel, all statuses in your Jira will be listed here for sorting. If one or more statuses are selected, the sort panel will display the list of selected columns (including Consolidated Columns) so you can select one of them. If you select a status that is not present in the report output, the sort will have no effect.
For assignee-based reports that support sorting, if no assignees are selected in Assignee panel, all assignees in your Jira will be listed here for sorting. If one or more assignees are selected, the sort panel will display the list of selected columns so you can select one of them. If you select an assignee that is not present in the report output, the sort will have no effect.
You can also sort the values by clicking the header of a report column. Subsequent clicks on the column header will alternate between ascending and descending sort directions.
When the data is sorted, a grey rectangle border appears on the outer layer of the Sort button to indicate that the data is being sorted.
An arrow showing the sort direction will also be shown in the sorted column's header. 
If the report type supports sort, aggregation reports support this as well. So you can sort the output for List, Average and Sum reports.
The sort selection also affects file exports.
Sorting requires all report data to be calculated so the first sort operation on the selected report dataset might take a little more time to calculate than usual. Subsequent sort operations on the same data should be quick.