I have 8 medium stand & 4 small stand; I see that the “Service round in Progress” never completes and my flights are getting delayed. Is this a Bug or how to make sure “Service round in Progress” completes on time…?
Make sure you have enough ramp agents,they really delay a plane if understaffed. I hire 2 for small stand, 4 for a medium stand and 5 per side of baggage bay,so 10 per bay, +10% extra overall for shift switching. So 44 ramp agents only for stands + baggage bays*10.
You also want to make sure they can take a break nearby, place some staffrooms nearby stands and inside the baggage bay rooms to reduce walking distance. Otherwise they lose already a lot of time walking.
I tried as you but it isn’t working …
What point do your service rounds normally get stuck at? Is it happening to all your flights?
Yes, Service round went fine for first flight, but after that it takes more then 8+ hours to complete per flight.
Here is the Save file.
https://drive.google.com/file/d/0B1ech49tc79XZU9KZFJrU1QyVkU/view?usp=sharing
I tested your save. The problem is not that service round is not working, the problem is that all tiles are unlocked and the terminal is so huge that it takes a long time for the ramp agents to calculate a path and make their way over to the stands. If I let it play for a few minutes some ramp agents do start the service round but it takes time. Unfortunately, I can only recommend you not to unlock the whole world at once and build a smaller terminal.
Ok, Thank you… 
This seems to be an issue still, however, it is much less of a problem. The service round completes at a glacial pace, despite there being 4 ramp agents at the stand and no baggage handling is going on.
Tip; build some “ramp agent” staff rooms near all stand clusters.
A good tip, but that doesnt do anything about having 4 standing there already at the stand staring at the plane instead of doing their service round. It does help if staff needs to rest and can do so much closer though.
Well, for a while all went just fine here, but now my airport starts struggling. It looks like my ramp agents need to think A LOT before the suitcase go from plane to cart or vise versa. He takes more than 5 ingame minutes before proceeding his task.
Example.
He drops the suitcase on the baggage cart one by one. When his hands are empty he waits, for at least 5 ingame minutes, before he starts moving again to get some more cases. One a 100 suitcases(they do like 4 at a time) they lose more than 2 hours! Thats a lot for just unloading the plane.
It is like all objects who calculate a path get slower and slower after a while. I think that when i’ve over 2k of pax there is too much pathfinding going on. My processor usages doesn’t seem to be divided equally either. (read something about multithreading not supported yet, but I can’t find it again) But are multiple cores supported? Because one core is like 80%used, 5 others doing nothing but a bit background processing <10% and 2 cores around 25%. A peak here and there, but no further exceptions. (I7 3610QM)
Not sure how the programming works, but if you could distribute the load more fair then wouldn’t it solve this kind issues? Or is it just in the pathfinding code where things go haywire?
This is my observations on ramp agents as well. Unloading and loading takes hours now, many minutes burned while they “think”.