Term
Definition
Cost Variance 
The difference between earned value and actual costs derived by subtracting actual costs from earned value.  A negative answer represents unfavorable cost performance. [Ref 6]
Coverage
Test Coverage: The degree to which a given test addresses all specified requirements for a given system or component.
Requirements Coverage: The degree to which a given set of tests addresses all known or implied requirements for a given system or component.  Requirements coverage applies to all test levels.
Code Coverage: The degree to which a given test or set of tests addresses all statements or paths in a given system or component.  Generally, this equates to unit and possibly string testing.
Coverage is usually measured as a percentage.
Decomposition
The process of drilling down into the technical and business requirements of a system to their lowest levels to create an inventory of testable requirements.
Earned Value 
The value of completed work expressed in terms of the budget assigned to that work.  Also referred to as budgeted cost for work performed. [Ref 6]
Function Points (FP) 
Alternative software sizing measure to Testable Requirements.  FP is a measure of delivered functionality that is relatively independent of the technology used to develop the system.
High Level Requirement (HLR)
The most generalized breakdown of requirements of the system.  Corresponds to major system functions or business processes.
Intermediate Level Requirement (ILR)
The next level of detail after High Level Requirements.  There may be several intermediate levels of requirements with increasing detail in each subsequent level.
Lines of Code (LOC) 
Alternative software sizing measure to Testable Requirements.  LOC is a measure of the size of the system that is built.  It is highly dependent on the technology used to build the system, the system design, and how the programs are coded.
Requirement
Condition or capability that is necessary for a system to meet its objectives.
Types of requirements [IEEE]:
functional
design
implementation
interface
performance
physical
Other common types:
business
user
program
operational
Risk 
The potential for a problem.
Risk Level
A number that denotes the amount of risk associated with not testing a requirement.  For example, 5 = critical risk, 3 = significant risk, 1 = minimal risk.  The detail of the risk levels depends on the complexity of the project.
Schedule Variance 
The difference between budget and earned value derived by subtracting budget from earned value.  A negative answer indicates that less work has been accomplished than was planned.  It may or may not represent a behind-schedule condition. [Ref 6]
Testable Requirement
A requirement that has been broken down to a level where it is precise, unambiguous, and not divisible into lower level requirements.
Test Case
Represents the specific detailed input and action steps taken during the execution of testing with predetermined expected results.  Usually, this involves very specific steps of action taken within the system, such as opening XYZ window, entering ABC data, and pressing V push button.