Measure-- provides a quantitative indication of the extent, amount, dimensions, capacity, or size of some attribute of a product or process.

Metric-- a quantitative measure of the degree to which a system, component, or process possesses a given attribute.

Indicator-- a metric or combination of metrics that provide insight into the software process, a software project, or the product itself.

Causes of defects and their origin
 

Design	Specification/Requirements	Code
Specifications 25.5%	Logic 20% Data Handling 10.5% Standards 6.9%	User Interface 11.7% Error Checking 10.9% Hardware Interface 7.7% Software Interface 6%

Size-Oriented Metrics

Size-oriented metrics are derived by normalizing quality and/or productivity measures by considering the "size" of the software that has been produced. (Ex. errors per KLOC, defects per KLOC, cost per KLOC, errors/person-month, etc.)

Function-Oriented Metrics

Functionality cannot be directly measured, so it must be derived indirectly using other direct measures. Albrecht suggested a measure called the function point, which is derived using an empirical relationship based on countable measures of software's information domain and assessments of software complexity.

After collecting the above data, a complexity value is associated with each count, and the function points are computed, using the following formula: FP = count-total x [0.65 + 0.01 x (sum)F sub i]

Function Point Links
Function Point FAQ
What are function points?
How are function points useful?
Auditing function point counts
PSI - Function point analysis

Suggested Links for Further Readings
Software Engineering Laboratory
U.S. Army software Metric System Web site
List of WWW references for software process metrics

Last Modified: Wednesday, 6-Jan-1999 9:30:00 CDT
Copyright © 1997-1999 University of Mississippi. All rights reserved.

Comments: reithel@bus.olemiss.edu