ethnographic observation: any technique in which observation of indirect and
direct factors inform the work of the requirements engineer.
feature points: an extension of function points that is more suitable for embedded
and real-time systems.
formal method: any technique that has a rigorous, mathematical basis.
function points: a duration and eﬀort estimation technique based on a set of proj-
ect parameters that can be obtained from the requirements speciﬁcation.
goal-based approaches: any elicitation techniques in which requirements are rec-
ognized to emanate from the mission statement, through a set of goals that
lead to requirements.
goal-question-metric (GQM): a technique used in the creation of metrics that can
be used to test requirements satisfaction.
group work: a general term for any kind of group meetings that are used during
the requirements discovery, analysis, and follow-up processes. JAD is a
form of group work.
GQM: see goal-question-metric.
informal method: any technique that cannot be completely transliterated into a
rigorous mathematical notation.
internal rate of return (IRR): a way to calculate an artiﬁcial “interest rate” for
some investment for the purposes of comparing the investment with
introspection: developing requirements based on what the requirements engineer
“thinks” the customer wants.
IRR: see internal rate of return.
JAD: see Joint Application Design.
Joint Application Design (JAD): elicitation technique that involves highly struc-
tured group meetings or mini-retreats with system users, system owners,
and analysts in a single venue for an extended period of time.
laddering: a technique where a requirements engineer asks the customer short
prompting questions (“probes”) to elicit requirements.
metrics abuse: an antipattern in which metrics are misused either through mis-
understanding, incompetence, or malicious intent.
model checker: a software tool that can automatically verify that certain properties
are theorems of the system speciﬁcation.
negative stakeholders: stakeholders who will be adversely aﬀected by the system.
net present value (NPV): a calculation to determine the value, in today’s dollars,
of some asset obtained in the future.
NFR: see non-functional requirement.
non-functional requirement (NFR): requirements that are imposed by the envi-
ronment in which the system is to operate.
NPV: see net present value.
performance requirement: a static or dynamic requirement placed on the soft-
ware or on human interaction with the software as a whole.