Notation For Theoretic Scheduling Problems - Job Characteristics

Job Characteristics

The processing time may be equal for all jobs (, or ) or even of unit length (, or ). This makes a difference because all release times, deadlines are assumed to be integer.

for each job a release time is given before which it cannot be scheduled, default is 0.

for each job a deadline is given after which it cannot be scheduled. If the objective is for example, then this field is implicitly assumed.

pmtn

the jobs may be preempted and execution resumed later, possibly on a different machine

Each job comes with a number of machines on which it must be scheduled at the same time, default is 1.

Precedence relations might be given for the jobs, in form of a partial order, meaning that if i is a predecessor of i' in that order, i' can start only when i is completed.

prec

an arbitrary precedence relation is given

sp-tree, tree, intree, outtree, chain

specific partial orders