Long term scheduling

Scheduling explicitly performed when a new process is created and it determines which programs are admitted to the system for processing. Therefore it controls the degree of multiprogramming. Formerly admitted it becomes a process and is added to the queue for the short term scheduler. It take on two decisions in the process creation that are First- the scheduler must decide that the operating system can take on one or more additional processes and Second- the scheduler must decide which job or jobs to accept and turn into processes.

The decision with regard to when to create a new process is usually driven by the desired degree of multiprogramming. Much the processes created smaller is the time that every process can be executed for.  The decision in respect of which job to admit next is able to be on a simple first come first serving basis or it can be a tool to manage system's performance. The criteria may comprise expected execution time, priority and IO requirements