Software Metrics & Software Metrology Alain Abran Chapter 1 Introduction

31 Pages·2010·0.24 MB·English

Software Metrics & Software Metrology
Alain Abran
Chapter 1 Introduction
© 2010 Alain Abran -Software Metrics & Software Metrology 1
This book includes 4 parts
 Part 1: Necessary concepts for a correct design of a software
measurement method
 including knowledge build over centuries in metrology
 Part 2: Examples to illustrate weaknesses in some of the most
popular ‘software metrics’
 Part 3: Example of a software measurement method built to
meet metrology & ISO requirements for software measurement
 Part 4: Examples of 2 key issues from metrology that are often
neglected in most ‘software metrics:
 Convertibility across distinct ‘metrics’ which claim to measure the same attribute
 A standard-étalon for measurement
© 2010 Alain Abran -Software Metrics & Software Metrology 2
Part 1 of this book
 Part 1 of this book present the necessary concepts for a correct
design of a software measurement method
 including knowledge build over centuries in metrology
•
Chapter 1 introduces some of the ambiguities in ‘software metrics’
and discusses their immaturity as technologies.
•
Chapter 2 presents a measurement context model to help clarify
the distinct concepts and steps in measurement
•
Chapter 3 presents the classical concepts of measurement
codified in the metrology body of knowledge that sustains
measurement in science and engineering
•
Chapter 4 discusses the differences between measurement in the
metrological sense and quantification
•
Chapter 5 discusses the design requirements for software
measurement methods
© 2010 Alain Abran -Software Metrics & Software Metrology 3
Agenda
This 1st chapter covers:
 Introduction to the term « metrics » & its ambiguities
 Software measurement: is it mature or not?
 Software measurement as a new technology
 The designs of software measures must be verified
© 2010 Alain Abran -Software Metrics & Software Metrology 4
Agenda
This 1st chapter covers:

Introduction to the term « metrics » & its ambiguities
 Software measurement: is it mature or not?
 Software measurement as a new technology
 The designs of software measures must be verified
© 2010 Alain Abran -Software Metrics & Software Metrology 5
Introduction to the term « metrics »
 In software engineering, the term “metrics” is used in reference to
multiple concepts.
For example:
•
the quantity to be measured (measurand [1]),
•
the measurement procedure,
•
the measurement results or
•
models of relationships across multiple measures, or
•
measurement of the objects themselves.

[1] A measurand is defined as a particular quantity subject to measurement [ISO
International Vocabulary of Metrology (VIM)].
© 2010 Alain Abran -Software Metrics & Software Metrology 6
Introduction to the term « metrics »
In the software engineering literature, the term was, up until recently,
applied to:
•
Measurement of a concept: e.g. cyclomatic complexity,
•
Quality models: e.g. ISO 9126 – software product quality, and
•
Estimation models: e.g.
 Halstead’s effort equation,
 COCOMO I and II – estimation models,
 Use Case Points,
 etc.
© 2010 Alain Abran -Software Metrics & Software Metrology 7
Introduction to the term « metrics »
Many curious problems have been identified:
 Proliferation of publications on metrics for concepts of interest,
but with a very low rate of acceptance and use by either
researchers or practitioners, as well as a lack of consensus on
how to validate so many proposals.
 Inventory of software metrics so diversified and with so many
individual proposals that it is not seen as economically feasible
for either the industry or the research community to investigate
each of the hundreds of alternatives proposed to date
•
Ex: to measure software complexity
•
To measure performance, etc.
© 2010 Alain Abran -Software Metrics & Software Metrology 8
Agenda
This 1st chapter covers:
 Introduction to the term « metrics »

Software measurement: is it mature or not?
 Software measurement as a new technology
 The designs of software measures must be verified
© 2010 Alain Abran -Software Metrics & Software Metrology 9
Software Measurement: Is it Mature or Not?
 The IEEE Computer Society defines software engineering as:
“(1) The application of a systematic, disciplined, quantifiable
approach to the development, operation, and maintenance
of software; that is, the application of engineering to
software.
(2) The study of approaches as in (1)” [IEEE 610.12]
 It is obvious that measurement is fundamental to software engineering
as an engineering discipline.
 But what is the status of measurement within software engineering,
and how mature is the field of knowledge on software measurement?
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