Routes- are they assigned or determined on seniority bids

[shon7]

Do the following airlines assign what route who will fly and when or do they let pilots bid on routes on the basis of seniority; the airlines in question-

Singapore Airlines

Thai Airways

Air India

Sri lankan

Thanks for your reples;

Lastly what context is the term crew rostering used in?

[411A]

SriLankan

Can't say just now, but when I worked there (1990's) the rosters were assigned, however pilots could make requests (and trade flights) which were nearly always granted.

Local Captains liked LHR but generally dis-liked NRT so personally received many more NRT flights. The system seemed to work pretty well and most everyone was satisfied.