Job associations are not assignments, rather they indicate that a person is "connected" to a job. For example, your volunteers who may do a job but do not come in on a fixed schedule. Use a job association to link the person to the job and give them the status of Active, Inactive, Leave of absence, Substitute, Pending, Preference, Waitlisted, Terminated, Transferred, Retired or Other.
Create a new job association
Once created, aspects of a job association can be edited but the job itself is fixed. To change the job, delete the existing job association and make another one.
Your administrator can configure job associations to use or not use dates, supervisors, locations and sports. You'll see different fields here, depending on which of these are enabled.