In swiftlets farming there are few stages that a farm will go thru that will justify the survival of the farm.
1)The ability to attract birds
This is the first and most important amongst all stages. If a farm is unable to attract birds to come in then it is of no use of taking about nests.
This has to do with the location , farm's design, entrance Hole position, Aroma ,quality of Int & Ext sound, etc.
2) The ability to make birds stay
This related to the Micros. The Aroma, Rh, Temp, Internal sound,etc. Any of these are not favorable to the birds then it would be hard for them to stay and make nest.
3) To increase the Population at a shortest time
The above 1 and 2 have to be in perfect condition and when both combined it would help to increase the bird's population thus nests will follow.
4) Quality of nest.
At this stage the micros still play an important role. The micros would affect the quality of the nest and the birds population.
5) To increase the number of nest
Good harvesting technique would help at this level. Improper harvesting technique that without planning and poor skill of harvesting will affect the number of nests.
At this stage a good micro would also help. A constant good micros are needed.
6)...... more............
7) .......more.....
8).......
9)......
10)....
Well I guess if one could do everything right till stage 5 then he will be laughing to the bank.
Good luck.