Requirements Engineering for Software and Systems

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Glossary

agile development: class of “lightweight” software development methodologies that

emphasize people over processes and feature a series of short development

increments.

antipattern: a situation involving an identifiable and non-unique pattern of nega-

tive behavior. e solution to an antipattern is called a refactoring.

assertion: a relation that is true at that instant in the execution of the program.

brainstorming: requirements elicitation technique that uses informal sessions with

customers and other stakeholders to generate overarching goals for the

systems.

card sorting: requirements elicitation technique that has stakeholders complete a

set of cards that include key information about functionality. e require-

ments engineer then groups the information logically or functionally.

client: see customer.

COCOMO: a tool that estimates software project effort and duration based on a

set of parameters that characterize the project. COCOMO is an acronym

for COnstructive COst MOdel.

customer: the class (consisting of one or more persons) who is commissioning the

construction of the system. Also called client or sponsor.

design constraint requirement: a requirement related to standards compliance

and hardware limitations.

designer as apprentice: a requirements discovery technique in which the require-

ments engineer “looks over the shoulder” of the customers to enable him

to learn enough about the customer’s work to understand their needs.

discounted payback period: the payback period determined on discounted cash

flows rather than undiscounted cash flows.

divergent goals: an antipattern in which two or more major players in a situation

are working against each other.

domain analysis: any general approach to assessing the “landscape” of related and

competing applications to the system being designed.

domain requirements: requirements that are derived from the application domain.

Extreme Programming (XP): an agile software development methodology.

230  Glossary

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

alternatives.

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.