Multiple processes can be scheduled to run across the scheduling landscape at any given time. Some of these jobs or job chains have dependencies that must be met and that forbid simultaneous execution. One simple way is to create a job chain that executes the jobs in a specific order, often however, one single job or job chain can only run once or when multiple other jobs or job chains have completed.

To prevent two identical jobs or job chains from running at the same time, locks can be used. A lock is an object that can be attached to a job or job chain and that prevents other jobs or job chains with that same lock from starting as long as a job with that lock is running.

An alternative solution, which is not recommended, would be to use a queue with a queue limit of 1, so only one job can run in the queue at any given time.