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A MODEL FOR VARIABILITY DESIGN RATIONALE IN SPLIsmênia Galvão, Pim van den Broek & Mehmet Akşit
VARI-ARCH 2010, Copenhagen, DK 23/08/2010
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INTRODUCTION
Beyond architecture variability specification…
Capturing and communication of the variability rationale
Explicitly handle the design rationale behind architectural variability
Capture assumptions about the design, its variants and invariants
Verification of the variability rationale
Consider that assumptions may become deprecated or invalidated
Detect violation of assumptions
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THE VARIABILITY RATIONALE MODEL ELEMENTS
Rationale A set of assumptions about artefacts
Assumption A statement about the design that is assumed to be true. Can be a claim or an assumed property.
Claim An assertion of a fact or belief.
Property SimpleProperty
VarianceProperty
A quality the system must have, what it must do or what it should not do.
Evidence The means by which a fact or belief can be estabilished or disproved.
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AN EXAMPLE OF ARCHITECTURE VARIABILITY
operation ControlCopy.copyPhoto is crosscutting
interface ControlCopy is optional
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AN EXAMPLE OF VARIABILITY RATIONALE
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What are the main stakeholders and their concerns with respect to variability?
Stakeholders*: Software architect
Software engineers
Product manager
Concerns: Communication of variability
rationale
Verification of design
Enhancement of variability design
Reuse
* All stakeholders that make relevant assumptions about the architecture variability
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With respect to which architectural models does the approach consider variability?
The assumptions about variability, defined using variance properties, can be captured for any architectural artefact, at any granularity level.
Sources and targets of claims may also reference any architecture element or variability model element.
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How do you integrate variability into a view-based architecture description?
Variability rationale is described within the rationale model, which is orthogonal to architecture models (e.g. component & connector) and to variability models (e.g. feature models).
The integration can be realized by querying the variability design rationale model (in Xtext). The resulting queries can be used to enhance the documentation of architecture variability in any architectural view.