Attributes are a very important source of requirements information. Just as every person has attributes (age, hair
color, gender), each requirement has a source, a relative importance, and time it was created. Attributes do more than
simply clarify a requirement. If created properly, they can yield significant information about the state of
the system. Just as you can run a database query to find all men with brown hair over age 30, given our human example,
you can run queries on the status of requirements to find all high-priority requirements from the customer in the
last 30 days. [TEL06]
Examples of attributes
Listed below is a partial list of some common attributes and a brief description of their meaning. Some attributes are
best described as a number, date, Boolean (true or false) or a text field for entering free format comments. Other
attributes can be expressed as lists. For instance, priority type is a list of high, medium, and low; Weekday is a list
which includes Monday, Tuesday, and so on.
Source - Person, document or other origin of a given requirement. This is useful for
determining whom to call for questions or for grouping requirements according to the person making the demands.
Priority - Statement of relative importance of the requirement, either to the system (mandatory, critical,
optional) or to other requirements (high, medium, low). It is good to track the mandatory or high-priority
items as an indication of how well the system will meet the greatest needs or for compliance-related metrics.
Assigned to - Who in the organization is responsible for making sure the requirement is met (person's name or
Comments - Reviewer's or writer's comments on a requirement.
Difficulty - An indication of the level of effort needed or how hard it will be to implement the requirement
(high, medium, low).
Status - Degree of completeness (completed, partial, not started).
Risk - Confidence measure on the likelihood of meeting (or not meeting) a requirement. Could be high, medium,
low or the integers one through ten.
Due By - Date the requirement must be provided.
Method of verification - Qualification type to be used to verify that a requirement has been met: analysis,
demonstration, inspection, test, and walkthrough.
Level of Test - Describes the verification lifecycle stage at which the requirement is determined to be met:
unit test, component, system or product.
Subsystem Allocation - Name of system or subsystem a requirement is to be assigned to (for instance, flight
control module, wing assembly, passenger cabin).
Test Number - Identification of a specific test or other method of verification.