Assessing software systems
Tudor Gîrba
www.tudorgirba.com

2002

PhD
2002 2005

PhD PostDoc
2002 2005 2009

PhD PostDoc
2002 2005 2009
Consultant
.ch
eng
ww.sw-
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complex, large
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= 250’000 lines of code

= 250’000 lines of code
* 2
= 500’000 seconds

= 250’000 lines of code
* 2
= 500’000 seconds
/ 3600 140 hours
~

= 250’000 lines of code
* 2
= 500’000 seconds
/ 3600 140 hours
~
/ 8 ~ 18 days

= 250’000 lines of code
* 2
= 500’000 seconds
/ 3600 140 hours
~
/ 8 ~ 18 days
/ 20 ~ 1 month

McCabe = 21
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McCabe = 21
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Metric Value
LOC 148‘760
NOM 14‘915
NOC 2’089
CYCLO 30‘073
CALLS 151287
FANOUT 85909
AHH 0.12
... ...

McCabe = 21
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A God Class centralizes too much intelligence
Class uses directly more than a
few attributes of other classes
ATFD > FEW
Functional complexity of the
class is very high
AND GodClass
WMC ! VERY HIGH
Class cohesion is low
TCC < ONE THIRD
6
scu 200
Marine
Lanza,

Significant duplication goes beyond just one line
Duplication chain has at least a
size of two relevant exact clones
SDC ! 2x(FEW+1)+1
Exact clones are longer than a
few lines of code Significant Duplication
AND
Chain
SEC > FEW
Distance between clones is not
more than a few lines of code
LB \" FEW
Significant standalone
exact clone
SEC > AVERAGE(LOC/Operation) Significant
OR
Duplication
6
scu 200
Significant Duplication Chain
Marine
Lanza,

McCabe = 21
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McCabe = 21
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How do programs look like today?

A picture tells
a thousand words

proximity

enclosure

connectivity

similarity

closure

continuity

A picture tells
a thousand words

es tell a
ot all ords
pictur
N
usand w
tho

System Complexity shows class hierarchies
03
asse 20
uc
anza, D
L

Distribution Map
shows properties
over structure
Ducass
e etal 200
6

Feature Map relates features to packages
7
etal 200
Greevy

CodeCity shows where your code lives
7
nza 200
La
Wettel,

and where your flaws live
8
0
ettel 20
W

Duplications shown side by side

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Hierarchy Evolution reveals evolution patterns
5
etal 200
Girba

Ownership Map reveals patterns in CVS
5
etal 200
Girba

Clone Evolution shows who copied from whom
6
etal 200
Balint

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e.ch
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ment is
assess
oftware
S
cy tools
han fan
ore t
m

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Tudor Gîrba
www.tudorgirba.com
creativecommons.org/licenses/by/3.0/