You can view the entire history of the card to see who has done certain actions with it and when.
To do this:
Open the card;
Click on the three dots below the name of the card;
Select "Show history".
You will see:
A scale that shows how long the card has been in each stage;
The time in operation and the waiting time;
Flow efficiency. It's the relation of the amount of time the card spent in the "In progress" type column to all the time the card was on the board. (e.g. the card was in the "In progress " type of column for 2 hours, the total time the card existed is 4 hours. 2/4 = 50%, so flow efficiency is 50%)
The date and time of the manipulation;
The author and time of manipulations.
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