(1) The condition allowing users to access and use their applications and data.
(2) The time periods during which a resource is accessible. For example, a contractor might have an availability of 9 AM to 5 PM every weekday, and 9 AM to 3 PM on Saturdays.
(3) The delivery of reliable service during scheduled periods
(4) The total amount of time that a resource can devote to new assignments.