GQM Presentation
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Transcript of GQM Presentation
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The Goal Question Metric Approach Victor R. Basili,
Gianluigi Caldiera
and H. Dieter Rombach
Presenter:
Jose Calvo-Villagran
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Overview
Motivations
GQM
Definition
Process
Examples
Extensions
Conclusions
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Motivations [1/2]
Measurement
Planning
Quality Control
Refinements
Progress
The case of Amisoft [2]
CPI/SPI
Volatility
Client incidents
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Motivations [2/2]
Effective measurement must be [1]:
Focused on specific goals
Applied to all cycles of production
Embedded into an specific context
Top down (?)
Quantitative model
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GQM: Definition [1/2]
Measurement system
Set of rules for interpretation of measurement data
Three levels
Conceptual Level [Goal]
Objects
Operation Level [Question]
Assessment
Quantitative Level [Metric]
Objective/Subjective
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4A GQM model is a hierarchical structure (Figure 1) starting with a goal (specifying
purpose of measurement, object to be measured, issue to be measured, and viewpoint
from which the measure is taken). The goal is refined into several questions, such as the
one in the example, that usually break down the issue into its major components. Each
question is then refined into metrics, some of them objective such as the one in the
example, some of them subjective. The same metric can be used in order to answer
different questions under the same goal. Several GQM models can also have questions and
metrics in common, making sure that, when the measure is actually taken, the different
viewpoints are taken into account correctly (i.e., the metric might have different values
when taken from different viewpoints).
In order to give an example of application of the Goal/Question/Metric approach, let's
suppose we want to improve the timeliness of change request processing during the
maintenance phase of the life cycle of a system. The resulting goal will specify a purpose
(improve), a process (change request processing), a viewpoint (project manager), and a
quality issue (timeliness). This goal can be refined to a series of questions, about, for
instance, turn-around time and resources used. These questions can be answered by
metrics comparing specific turn-around times with the average ones. The complete
Goal/Question/Metric Model is shown in Figure 2.
Figure 2
Goal Purpose Improve
Issue the timeliness of
Object (process) change request processing
Viewpoint from the project manager's viewpoint
Question What is the current change request processing
speed?
Metrics Average cycle time
Standard deviation
% cases outside of the upper limit
Question Is the performance of the process improving?
Metrics Current average cycle time
Baseline average cycle time100*
Subjective rating of manager's satisfaction
3. THE GOAL QUESTION METRIC PROCESS
GQM: Definition [2/2]
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GQM: Process
Identify goals
Policies/Strategies
Description of process/product
Model of the organization
Derive questions
How to characterize the object?
How to characterize the attributes?
How to evaluate the characteristics?
Specify metrics
Amount and quality of data
Maturity of objects
Learning process
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GQM: Remarks
Simple, intuitive approach for specifying metrics
Metrics can be reused by several questions
Four phases: [3]
Planning
Definition
Collection
Interpretation
Goals include different viewpoints (stakeholders)
Subjective metrics
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Examples [1/2]
[4]
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Examples [2/2]
The purpose is to characterize the effect of pair programming on programmer effort and program quality from the point of view of software managers in the context of a small web-development company [5].
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*Side notes
Applicable on mature organizations:
Employee involvement (resistance)
Clear goals
Gradual/Slow changes
Does GQM evolve over time? How fast?
Does GQM apply to more agile environments?
Why GQMs main focus is SE?
Simplicity: Double edged sword
Relation between goals
How do GQMs goals align with organizations goal?
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Extensions
GQM+Strategies [6]
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Conclusions
Top-down approach for definition and collection of metrics
3 levels & 4 phases
Applied to all phases of software development
Requires organizational maturity
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Bibliography
[1] Victor Basili, Gianluigi Caldiera, Dieter Rombach. 1994. The Goal Question Metric Approach.
[2] Romain Robbes, Rene Vidal, Maria Cecilia Bastarrica. 2013. Are software analytics efforts worthwhile for small companies? The case of Amisoft. IEEE
[3] Irene Eusgeld, Feliz Freiling, Ralf Reussner. 2008. Dependability Metrics: Advanced Lectures.
[4] D.Ernst, F. Houdek. GQM Method Application. Taken on 27-Jan-2013. http://www-ivs.cs.uni-magdeburg.de/sw-eng/us/java/GQM/link3.shtml
[5] http://en.wikipedia.org/wiki/GQM
[6] Victor Basili, et. al. 2010. Linking software development and business strategy through measurement. IEEE