CSE360
Introduction to Software Engineering
Lecture 24:
Software Measurement
Javier Gonzalez-Sanchez
[email protected]
javiergs.engineering.asu.edu
Office Hours: By appointment
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Let’s Make a Parenthesis
To talk about Quality
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Quality
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Software Metrics
• Knowing what is inside your source code is the first
step in assessing the quality of the software product.
• Knowing the quantity of work performed in
generating the source code is the first step in
determining the productivity of your software team.
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Software Metrics
Metrics
Size
LOC
eLOC
lLOC
Understandability
Comments
Whitespaces
Complexity
Average, Max, Min LOC
Interface Complexity
Cyclomatic Complexity
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Size Metrics
• LOC – Lines of Code Metric. Including lines of a
single brace or parenthesis
• LOC are used to create time and cost estimates.
• LOC are a tracking tool to measure the degree of
progress on a module or project.
• An experienced developer can gage a LOC
estimate based upon knowledge of past
productivity on projects.
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Size Metrics
• eLOC – effective Lines of Code Metric. Only code
statements
• An effective line of code or eLOC is the
measurement of all lines that are not comments,
blanks or standalone braces or parenthesis. These
can inflate LOC metrics by 20 to 40 percent.
• This metric more closely represents the quantity of
work performed.
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Size Metrics
• lLOC – logical Lines of Code Metric.
• These statements are terminated with a semi-
colon. The control line for the "for" loop contain two
semi-colons but accounts for only one semi colon.
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Example
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Understandability Metrics
• Comment Line and Comment Percent Metric
• The degree of commenting within the source code
measures the care taken by the programmer to make
the source code and algorithms understandable.
• Poorly commented code makes the maintenance
phase of the software life cycle an extremely expensive
adventure.
• Comments can occur by themselves on a physical line
or be co-mingled with source code. The sum of the lines
of code, comments and blank lines often exceeds the
physical line count. This is expected a when comments
are co-mingled with source code.
• Comment Percent =
Comment Line Count / (LOC) x 100
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Understandability Metrics
• Blank Line and White Space Percent Metric
• The number of blank lines within source code determines
the readability of the product. White space accents the
logical grouping of constructs and variables. Programs
which use few blank lines are difficult to read and more
expensive to maintain.
• It counts the spaces and characters within the source
code. The white space percentage metric is another
measure of readability for the source product.
• White Space Percentage = (Number of spaces / Number
of spaces and characters) * 100
CSE360 – Introduction to Software Engineering
Javier G onzalez-Sanchez
javiergs@ asu.edu
Sum m er 2017
Disclaim er. These slides can only be used as study m aterial for the class C SE360 at ASU. They cannot be distributed or used for another purpose.