Definition
Machine
A machine in scheduling is a resource that can process jobs over time.
Formally, a scheduling instance has a finite machine set
In the basic model, each machine can process at most one job at any time.
Capacity
Non-overlap
If jobs and are assigned to the same machine, then their processing intervals must not overlap:
Role
In interval scheduling, there is one machine and the objective is to select a maximum compatible subset of jobs.
In interval partitioning, every job must be processed and the objective is to minimise the number of machines.