dib 1 component characterization: proposal and empirical assessment pasquale ardimento – phd...
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DIB 1
Component characterization:proposal and empirical
assessmentPasquale Ardimento – Phd Candidate
Serlab - Dept of Informatics - University of BariRCost Bari
ardimento@di.uniba.itDepartment of Computation, UMISTManchester 16th September, 2004
Component Characterization
DIB 2
Component-based Software Development
Component-Based Software Engineering (CBSE) promises to reduce complexity and cost of software processes
but it introduces difficulty in identifying the most appropriate
components, which satisfy specific requirements for a target Components-Based System (CBS)
difficulty in learning the component features
Component Characterization
DIB 3
Impact of component choice
The choice of the adequate component is a critical activity because of asynchronous evolutions between CBS and
components integrated in it various and numerous features of both the
organizations and of the systems to develop
the most significant aspectsof components must be known
Component Characterization
DIB 4
Our research
perform empirical studies, aimed at identifying the most significant or relevant characteristics of components
we have identified a set of component characteristics Adequacy Adoption cost Familiarity Support
Component Characterization
DIB 5
Purpose
evaluate the effectiveness of this set wrt a maintainability quality factor
To this end a quality factor in the CBS has been identified the effectiveness of component characteristics
has been evaluated wrt the maintainability quality factor
Component Characterization
DIB 6
Post-Mortem Analysis
Data of three industrial CBSs SICOD: a CBS supporting the qualification of education
and scientific services offered by the University of Bari DiPNET: a Web-Portal supporting different companies
cooperating for the development of a project Portal: the Web-Portal currently used by University of
Bari; it provides a unique point of access to a number of services and information the university offers to its stakeholders
The changes concerned corrective, adaptive and perfective maintenance
Component Characterization
DIB 7
Component Characteristics and Metrics...
Adequacy Functional coverage - the percentage of the
CBS functionalities provided by a component wrt to the total number of functionalities the CBS provides
Compliance - the percentage of the CBS functionalities provided by a component wrt to the total number of functionalities the component makes publicly available
Component Characterization
DIB 8
...Component Characteristics and Metrics
Adoption cost Training time - the working time spent for
training people involved in the integration of components
Familiarity the understanding of a component
Support the level of support provided by the vendor
Component Characterization
DIB 9
Metrics and measurement scales
Characteristic Metrics ScaleAdequacy Functional
CoverageRatio (percentage)
Compliance Ratio (percentage)
Adoption cost Training cost Ratio (working days)
Familiarity Familiarity Ordinal (Low, Medium, High)
Support Support Ordinal (Low, Medium, High)
Component Characterization
DIB 10
Quality factor
Mean Maintenance Effort (MME) MMEj represents the effort spent to satisfy maintenance
requests in the j-th component of the CBS
whereMEi,j is the effort spent for satisfying the i-th maintenance
request of the j-th componentr is the total number of maintenance requestsn is the total number of components in the CBS
nMME
r
iji
j
ME 1
,
Component Characterization
DIB 11
Normalization
Values assumed by TT and MME measures are very different among the three projects
these factors had to be normalized
Normalization factor: and so we have:
n
jjVNF
1
n
jj
jj
TT
TTNTT
1
n
jj
jj
MME
MMENMME
1
Component Characterization
DIB 12
Research Questions
Is there any correlation between characterization metrics and quality factor metrics?
if so, are the relationships due to specific features of the projects, or are they independent from them?
Investigation
Training timeFunctional Coverage
ComplianceFamiliaritySupport
Mean Maintenance Effort
Component Characterization
DIB 13
Mutual Independence of characterization measures
FunCov Compl NTT Familiarity Support
FunCov 0,056 0,554 0,900 0,238
Compl 0,056 0,213 0,272
NTT 0,554 0,213 0,186 0,058
Famil. 0,900 0.985 0,186 0,456
Support 0,238 0,272 0,058 0,456
Results show that characterization measures are independent from each other
Component Characterization
DIB 14
Relationship between NMME and characterization measures
Variables P-level Correlation
Functional Coverage 0,502
Compliance 0,111 0,413 NO
NTT 0,634
Familiarity 0,953 0,015 NO
Support -0,687
0,047 YES
0,008 YES
0,003 YES
Component Characterization
DIB 15
Differences among projects …
Are the relationships between characterization metrics and quality factors metrics due to specific features of the projects or are they independent from them?
H0: null hypothesis some statistically significant difference exists among the
three projects with respect to those measures
H1: alternative hypothesis no statistically significant difference exists among the
three projects with respect to those measures
Component Characterization
DIB 16
… Differences among projects
Variable
P-level among projects
SICOD-DiPNET SICOD-Portal DiPNET-PortalSICOD-DiPNET-Portal
FunCov 0,070 0,738 0,794 0,254
NTT 0,401 0,317 0,191 0,321
Support 0,4385 0,404 0,695 0,475
NMME 0,518 0,504 0,794 0,745
Correlations are independent from specific features of the three projects
Component Characterization
DIB 17
Correlation between component characteristics & MME
Functional Coverage & NMME The higher is Functional Coverage the higher is the probability that a
change in CBS impacts that component Lesson learned: CBS functionality should be concentrated over a single
aspect of the application domain
Training Time & NMME components vendors propose training period depending on intrinsic
difficulty in managing the components Lesson learned: High training usually indicates the complexity of
understanding a component and this implies high maintenance effort
Support & NMME problems faced during maintenance can be faced making use of the
provided support Lesson learned: a deep knowledge of the component is necessary to
avoid the risk that the offered TT is not adequate for comprehending the needed component
Component Characterization
DIB 18
Absence of correlation
Compliance Maintenance effort of a component does not
depend on the amount of its usage but on the component itself
Familiarity During maintenance activity further unfamiliar
aspects can be required even when the developer and the maintainer are the same person
Component Characterization
DIB 19
Effectiveness of the proposed set of characteristics
The metrics Functional coverage Training time Support
resulted to be effective in characterizing the MME quality factor of Components to be maintained in a CBS
Component Characterization
DIB 20
Threats
Following threats have been avoided randomness and irrelevancies of people, tools
and processes used within all projects heterogeneity of experimental subjects the treatment is unique for all project
Following threats have not been avoided Reliability of measures Set of experimental subjects Set of experimental objects
Component Characterization
DIB 21
Future Works…
Since the current study concerned only three heterogeneous projects some threats have been poorly considered
further investigations are needed to analyse further characteristics and quality factors, which
can be meaningful for choosing components validate the cause – effect relationship between
characteristics and maintenance effort it will also be necessary to organize metrics
collection through more effective techniques and tools than interviews
Component Characterization
DIB 22
…Future Works
Following characteristics have still to be investigated Integration technique Interface stability portability Maintenance effort (a greater detail) Rating (open source) Adherence to standards (open source)
Component Characterization
DIB 23
Publications on this topic
Bianchi A., Caivano D., Conradi R., Jaccheri L., Torchiano M., Visaggio G., “COTS Products Characterization: Proposal and Empirical Assessment”, in R.Conradi and A.I. Wang (Eds.), Empirical Methods and Studies in Software Engineering – Experiences from ESERNET, Lecture Notes in Computer Science 2765 (2003), 233-255.
P.Ardimento, A.Bianchi, G.Visaggio, “Maintenance-oriented selection of software components”, CSMR2004, Tampere Finland, March: 24-26, 2004
P.Ardimento, T. Baldassarre, A. Bianchi, “Verso una caratterizzazione delle Componenti Software”, AICA2004, Benevento Italy, September 2004
Component Characterization
DIB 24
SICOD
A CBS supporting the qualification of education and scientific services offered by the University of Bari
Components integrated in it are Oracle 9i Oracle Internet Application Server 9i Oracle Report Builder and Crystal Report Applix iEnterprise Plumtree Corporate Portal 4.5
Component Characterization
DIB 25
DiPNET
a Web-Portal supporting different companies cooperating for the development of a project
Components integrated in it are SQL Server 7 SNITZ Forum DatePicker MS ADO, COM objects Internet Information Services (IIS) MS Index Server (IIXSO) MS Collaboration Data Objects for NT (CDONTS)
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