The maintenance elements are defects, changes, issues and tasks. They all apply to individual model elements and can be used to record and capture problems, changes, issues and tasks as they arise, and document the solution and associated details. They are defined as follows:
|·||A defect can be considered as a failure to meet a requirement for the current model element|
|·||A change can be considered as a change in requirement for the current model element|
|·||An issue is a record of a risk or other factor that might affect the project being recorded for the current model element|
|·||A task is a means of recording work in progress and work outstanding for the current model element.|
Note that each of these maintenance elements applies at the model element level. For changes and issues that apply to the whole system, see the Changes and Defects topic; for tasks that apply to the whole system, see the Project Tasks topic.