The role of first line managers is basically supervisory in nature,they supervise the activities of medical representative and ensure that all the plans of compny are implemented by the grass root workers,that is a m.r.
This role can be played only by first line managers as they are close to mr most of the time,second line managers can not be with every m r every month so they can not ensure implementation by each m.r.
The first line managers are implementors of the company's strategy,their job is see that a m.r implements the compny' strategy in the field. They play low role in planining
the second line managers and above come under senior managers like zsm/sm they play key role in business planning which is suppose to be implemented by first line managers and m r.
So the basic difference between first and second or third line jog function is that the first is implementor while the second and third line manger have to do lot in terms of planing,they dont just implement.
More diffrences i would like to tell you in my next writing. Hope this will clear you some of basics.
Amar bir singh
24th February 2011 From India, New delhi