Software evolution often leads to the degradation of software design quality. In Object-Oriented (OO) systems, this often results in packages that are hard to understand and main- tain, as they group together heterogeneous classes with unrelated responsibilities. In such cases, state-of-the-art re-modularization tools solve the problem by proposing a new organization of the existing classes into packages. However, as indicated by recent empirical studies, such approaches require changing thousands of lines of code to implement the new recommended modularization. In this demo, we present the implementation of an Extract Package refactoring approach in ARIES (Automated Refactoring In EclipSe), a tool supporting refactoring operations in Eclipse. Unlike state-of-the-art approaches, ARIES automatically identifies and removes single low-cohesive packages from software systems, which represent localized design flaws in the package organization, with the aim to incrementally improve the overall quality of the software modularisation.

1. Extract Package
Refactoring in ARIES
Fabio Palomba*, Michele Tufano❊
, Gabriele Bavota#,
Rocco Oliveto✢
,Andrian Marcus†, Denys Poshyvanyk❊
,Andrea De Lucia*
* University of Salerno
❊
The College of William and Mary
# Free University of Bozen-Bolzano
✢
University of Molise
† University ofTexas

2. Cohesion
Coupling

3. SOFTWARE QUALITY DESIGN
DECREASES OVERTIME

4. How to solve the problem?
Big Bang Software re-modularization
A complete re-organization of the system’s classes into packages

5. “Big- Bang” re-modularization is not a viable
solution since even for modest systems, the
number of changes required to apply it is in the
order of thousands of lines of code”
M. Hall, M. Khojaye, N.Walkinshaw, and P. McMinn
“Establishing the source code disruption caused by automated remodularization tools”
ICSME 2014
How to solve the problem?

6. Thus, re-modularization efforts need to be localized,
and aimed at solving specific design issues.

7. G. Bavota,A. De Lucia,A. Marcus, R. Oliveto
“Using Structural and Semantic Measures to Improve Software Modularization”
EMSE
A Graph-theory based Approach for Extract
Package Refactoring

8. A Graph-theory based Approach for Extract
Package Refactoring
n classes
Package P

9. A Graph-theory based Approach for Extract
Package Refactoring
class-by-class
matrix construction
c2
. . . . . . . .
cn
c1
n classes
Package P
c1 c2 ........ Cn

10. A Graph-theory based Approach for Extract
Package Refactoring
class-by-class
matrix construction
c2
. . . . . . . .
cn
CCBC ICP
Conceptual Coupling
Between Classes
Information flow-based
Coupling
c1
n classes
Package P
c1 c2 ........ Cn

11. A Graph-theory based Approach for Extract
Package Refactoring
class-by-class
matrix construction
c2
. . . . . . . .
cn
CCBC ICP
Conceptual Coupling
Between Classes
Information flow-based
Coupling
ci,j = wCCBC ·CCBC + wICP · ICP
c1
n classes
Package P
c1 c2 ........ Cn

12. A Graph-theory based Approach for Extract
Package Refactoring
c2
. . . . . . . .
cn
c1
c1 c2 ........ Cn
class-by-class matrix
filtering and transitive clousure
0.8
0.70.5
0.7
0.6
Chain 1
Chain 2Chain 3

13. A Graph-theory based Approach for Extract
Package Refactoring
c2
. . . . . . . .
cn
c1
c1 c2 ........ Cn
class-by-class matrix
filtering and transitive clousure
0.8
0.70.5
0.7
0.6
Chain 1
Chain 2Chain 3

14. A Graph-theory based Approach for Extract
Package Refactoring
c2
. . . . . . . .
cn
c1
c1 c2 ........ Cn
class-by-class matrix
filtering and transitive clousure
0.8
0.70.5
0.7
0.6
Chain 1
Chain 2Chain 3
0.8
0.70.5
0.7
0.6
Chain 1
Chain 2Chain 3
merging trivial
chains
Chain 1
Candidate Package 1
Chain 2
Chain 3
Candidate Package 2

15. An Eclipse Plugin to Automate
Refactoring Operations

16. Extract Package
Refactoring in ARIES
Fabio Palomba
University of Salerno
fpalomba@unisa.it
dibt.unimol.it/fpalomba
MicheleTufano
The College of William and Mary
mtufano@email.wm.edu
www.cs.wm.edu/~mtufano/
Q&A
Thank you!