Bag drop : 1 step or 2 steps ?

The bag process refers to tagging and injection of the bag in the BHS (baggage handling system).
2 broad options are available : either tagging is performed away from drop off (2-step process) or tagging is performed at the drop off point (1-step). There are advocates for both solutions.
The 2-step process is implemented in Canada, Scandinavia, New Zealand,...
The one-step process is implemented in UAE, Germany,... Supporters of the 1-step process claim that it is more passenger friendly. The main argument is that passengers that come to the airport and have already checked in only need to make one stop at the drop off station. The second perceived benefit is that the system is simpler because there is no need for a tagging station.
The supporters of the 2-step process analyze the situation differently. Tagging a bag takes longer than dropping a bag (see self tagging and bag drop articles). This means that the bag drop station will be mobilized for a long period of time during which it is useless (tagging). To avoid this, the process can be split into 2 steps in which resources will be optimized independently. Tagging will be performed on tagging stations (such as self-service kiosks equipped with bag tag printers). Bag injection will be performed on another equipment (self-service or not). As tagging takes longer than bag injection, the quantity of tagging stations will be greater than the one of bag injection. Another benefit is that bag tag refilling can be made without mobilizing the drop off station.
So, what process to choose ?
The decision will be dependent upon the level of saturation at peak time. If there are no queues at peak time, then a 1 step process is probably a good solution.
But if you have queues at check-in at peak hour then the choice is clear : 2-step process. Doing so you will reduce the time that passengers spend on the bag drop position. These positions are the major constraint because their number cannot be increased without heavy civil engineering work. As tagging takes more time, you will require approximately 3 to 4 tagging stations per bag drop position. Installing many kiosks for self tagging should not an issue as their footprint is reduced. Their ideal position is 3 to 4 meters away from bag drop area. Which such a lay out your resources will be well balanced and the total capacity of the system will be approximately two times (depending on the performance of your check in) higher than regular counters.