>Hi,
>My class is a leave manager class. It responsible for anything related to leave. For example, approve leave, get pending leave list, cancel leave and etc. We have different developer responsible for each of the methods to speed up the development during the tight schedule timeline.

Exactly! A manager object manages other objects. So have the manager object instantiate other objects that approve leave, cancel leave etc.

Further put each of these objects in their own classlibs and you won't have to use source control to knit the classes back into the one classlib.