Package Data Abstraction Coupling ( )

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Package Data Abstraction Coupling ( )

Works with all instances of a common meta-model, regardless of whether they were produced with the Java or the UML front-end. The respective extends (Java) or generalization (UML) relations expressing the inheritance between two classes are mapped onto relations of type inheritance in the common meta-model (and the

specific view).

Handle

Description

The PDAC measures the coupling complexity caused by ADTs on package level. Based on DAC it transfers the effects of the coupling between classes on the reuse degree, maintenance and testing effort to more abstract organization units like packages and modules, which are as well decisively influenced by the coupling between classes of different packages.

Scope

Package

View

${V}^{PDAC} = ({G}^{PDAC}, {R}^{PDAC})$

Grammar ${G}^{PDAC} = (\{\textrm{class}^{PDAC}, \textrm{package}^{PDAC}\}, \emptyset,\\ \textrm{package}^{PDAC})$
Relations $\\ {R}^{PDAC}: \{\textrm{referencestype}^{PDAC} : \textrm{class}^{PDAC} \times... ...extrm{contains}^{PDAC} : \textrm{package}^{PDAC} \times \textrm{class}^{PDAC}\}$

Mapping $\alpha^{PDAC}$ :

$\displaystyle \alpha^{PDAC}(\textrm{Class})$	$\displaystyle \mapsto$	$\displaystyle \textrm{class}^{PDAC}$
$\displaystyle \alpha^{PDAC}(\textrm{Package})$	$\displaystyle \mapsto$	$\displaystyle \textrm{package}^{PDAC}$
$\displaystyle \alpha^{PDAC}(\textrm{IsOfType})$	$\displaystyle \mapsto$	$\displaystyle \textrm{referencestype}^{PDAC}$
$\displaystyle \alpha^{PDAC}(\textrm{Contains})$	$\displaystyle \mapsto$	$\displaystyle \textrm{contains}^{PDAC}$

Definition

The

value of a package $p \in package^{PDAC}$ is defined as:

$\displaystyle C(p)$	$\displaystyle =$	$\displaystyle succ(p, \textrm{contains}^{PDAC})$
$\displaystyle PDAC(p)$	$\displaystyle =$	$\displaystyle \left\vert succ(C(p), \textrm{referencestype}^{PDAC}) \backslash C(p) \right\vert$

Scale

Absolute.

Domain

Integers $\in 0..\infty$ .

Highly Related Software Quality Properties

Re-Usability 2.4

is negatively influenced by coupling.

Understandability for Reuse 2.4.1:: A part of a system that has a high (outgoing) efferent coupling may be highly inversely related to understandability, since it uses other parts of the system which need to be understood as well.
Understandability decreases with increasing PDAC.
Attractiveness 2.4.4:: Parts that have a high (outgoing) efferent coupling may be highly inversely related to attractiveness, since they are using other parts of the system which need to be understood as well, and represent dependencies.
Attractiveness decreases with increasing PDAC.

Maintainability 2.6

decreases with increasing PDAC.

Analyzability 2.6.1:: Parts that have a high (outgoing) efferent coupling may be highly inversely related to analyzability, since they are using other parts of the system which need to be analyzed as well.
Analyzability decreases with increasing PDAC.
Changeability 2.6.2:: Parts that have a high (outgoing) efferent coupling may be inversely related to changeability, since they are using other parts of the system which might need to be changed as well.
Changeability decreases with increasing PDAC.
Stability 2.6.3:: Parts showing a high (outgoing) efferent coupling may be inversely related to stability, since they are using other parts of the system, which are can affect them.
Stability decreases with increasing PDAC.
Testability 2.6.4:: Parts that have a high (outgoing) efferent coupling may be highly inversely related to testability, since they are using other parts of the system which increase the number of possible test paths.
Testability decreases with increasing PDAC.

Portability 2.7

decreases with increasing PDAC.

Adaptability 2.7.1:: Parts that have a high (outgoing) efferent coupling may be inversely related to adaptability, since they are using other parts of the system which might need to be adapted as well.
Adaptability decreases with increasing PDAC.

Related Software Quality Properties

Functionality 2.1

is both negatively and positively influenced by coupling.

Interoperability 2.1.3:: Parts that have a high (outgoing) efferent coupling may be directly related to interoperability, since they are using/interacting with other parts of the system.
Interoperability might increase with increasing PDAC.
Security 2.1.4:: Parts that have a high (outgoing) efferent coupling may be inversely related to security, since they can be affected by security problems in other parts of the system.
Security might decrease with increasing PDAC.

Reliability 2.2

might decrease with increasing PDAC.

Fault-tolerance 2.2.2:: Parts that have a high (outgoing) efferent coupling may be inversely related to fault-tolerance, since they can be affected by faults in other parts of the system.
Fault-Tolerance might decrease with increasing PDAC.
Recoverability 2.2.3:: Parts that have a high (outgoing) efferent coupling may be inversely related to recoverability, since their data is distributed in other parts of the system making their recovery difficult.
Recoverability might decrease with increasing PDAC.

Re-Usability 2.4

might decrease with increasing PDAC.

Learnability for Reuse 2.4.2:: Parts that have a high (outgoing) efferent coupling may be inversely related to learnability, since they are using other parts of the system which need to be understood as well.
Learnability might decrease with increasing PDAC.
Operability for Reuse - Programmability 2.4.3:: Parts that have a high (outgoing) efferent coupling may be inversely related to learnability, since they are using other parts of the system, which represent dependencies.
Programmability might decrease with increasing PDAC.

Efficiency 2.5

might decrease with increasing PDAC.

Time Behavior 2.5.1:: Parts that have a high (outgoing) efferent coupling may be inversely related to time behavior, since they are using other parts of the system, thus execution during test or operation does not stay local, but might involve huge parts of the system.
Time behavior might get worse with increasing PDAC.
Resource Utilization 2.5.2:: Parts that have a high (outgoing) efferent coupling may be inversely related to resource utilization, since they are using other parts of the system, thus execution during test or operation does not stay local, but might involve huge parts of the system.
Resource utilization might get worse with increasing PDAC.

References

PDAC is implemented in the VizzAnalyzer Metrics Suite.

Since

Compendium 1.0

Next: Cohesion Up: Coupling Previous: Message Passing Coupling (