Air Canada has implemented self check-in at Pearson Airport in Toronto. For all flights, you no longer go to an attendant to obtain you boarding pass, you enter all the required data into a computer, and then check your bags.
This was supposedly done for efficiency reasons. However, most of the efficiencies in the system have been lost. Amazingly, when you get to the front of the second line (to check in your bags), the check in clerk does exactly the same amount of work as before. The first thing they do is verify all of the details that you provided the computer!
Let's go over that again. After having provided my information to a computer, I have to provide it a second time to a human who verifies the first data. The time taken for verification was exactly the same as it would have taken for them to key it in in the first time. Instantly, you have a net loss of efficiency. Even worse, they only have a single set of scales for each pair of desks. That means that there is substantial dead time while you wait for the person at the desk next to you to finish weighing their bags. More lost efficiency.
I can see how it happened. Someone checked in to the wrong flight, or their bags went to the wrong place. Perhaps they got to US customs (you go through US customs in Canada when flying to the US), and didn't have the correct forms or all their data provided, and were sent back, maybe they even missed a flight.
So, the check-in clerks, who are also looking to protect their jobs, add in the task of checking customer provided data.
However, they don't check the data of people who don't have checked baggage, they go straight through to customs. This shows the stupidity of the additional check. Is Air Canada saying that people with checked luggage are more likely to enter incorrect data? I doubt it.
If you make efficiency gains in your organisation, make sure you protect them. Guard them jealously. If you don't, you will see them frittered away.