This document presents the UCM2PCM tool, which rapidly transforms use case maps (UCM) models into Palladio component models (PCM) to enable early performance modeling. It aims to address challenges in modeling complex control/data flows and allocating global response time budgets. The tool was evaluated on three systems and found to produce PCM models with performance results within 15% of manual models. A user survey also found the tool made performance modeling more comprehensible and faster for non-experts. Future work includes improving the tool's input assistance and enabling reverse transformation from PCM back to UCM.

1. Rapid Performance Modeling
by transforming Use Case Maps
to Palladio Component Models
Christian Vogel (KIT), Heiko Koziolek (ABB), Thomas Goldschmidt (ABB), Erik Burger (KIT)
© ABB Group
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2. Motivation
Performance Modeling at ABB
 Industrial Automation Domain
 Efficient control/data flow
crucial for real-time constraints
 Design sketches on whiteboards
 End-to-end latency as a requirement
 Challenges
 How to reason on
complex control/data flows?
 How to break down global response time
requirements to performance budgets
for software components?
© ABB Group
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Sketch
of a simple
webserver

3. Solution Approach
UCM2PCM
 Palladio Component Model (PCM) allows
consideration and prediction of
performance from the beginning
 But
 Control flow and structure in different
views
 PCM models are difficult to create
for persons from industrial automation
 Thus
 Use Case Maps (UCM) as new
frontend for PCM
 Transformation from UCM to PCM
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4. Related Work
Model transformations in SW Performance Engineering
 Performance engineering
 C. Smith and L.Williams, Addison-Wesley (2002)
Performance Solutions: a practical guide to creating responsive, scalable software
 D. Menasce, L.W. Dowdy, V. Almeida, Prentice Hall (2004)
Performance by design: computer capacity planning by example
 Survey of approaches for performance predictions
 S. Balsamo, A. Di Marco, P. Inverardi, and M. Simeoni, IEEE TSE (2004)
Model-based performance prediction in software development: A survey
 H. Koziolek, Elsevier Performance Evaluation (2010)
Performance evaluation of component-based software systems: A survey
 Transformation of UCM into Layered Queuing Networks (LQN)
 D. B. Petriu (2001)
Layered software performance models constructed from use case map specifications
 Use of UML Marte Profile for creating performance models
 M. Woodside (2007)
From annotated software designs (UML SPT/Marte) to model formalisms
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5. Foundations
Use Case Maps
 Scenario-based modeling
language
 Part of the User Requirements
Notations (URN)
 Intuitive and easy to learn
 Graphical editor exists*
 Allows specification of
performance annotations
© ABB Group
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* http://lotos.site.uottawa.ca/ucm/bin/view/ProjetSEG/WebHome

6. UCM2PCM
Architecture
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7. UCM2PCM
Performance Annotations added to UCMs
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Loop IterationCount Resource Demands
Component AllocationBranch Probabilities
Scenario Workload

8. UCM2PCM
Mapping Approach
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UCM Path
Component
Responsibility

9. UCM2PCM
Mapping Approach
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Return Call
Component Call
All calls

10. UCM2PCM
Mapping Approach
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SystemRequiredCall
SystemProvidedCall
ParentCall

11. UCM2PCM
Mapping Approach
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Usage Model

12. UCM2PCM
Limitations
 Limited Input Assistance
 Performance Annotations need to be added as key-value pairs
 Limited PCM feature support
 Variables & Guarded Branches are not supported
 No Customized ResourceEnvironment supported
 Duplicated SEFFs
 For every call of a function a new SEFF is created
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13. Evaluation
Goals
 Evaluation of Accuracy
 Apply UCM2PCM to three test systems
 Validate the correctness of the PCM models
resulting from the UCM2PCM transformation
 Measure and check the accuracy of the produced
SimuCom performance results
 Evaluation of Usability
 Tutorial & Assignment for UCM2PCM
 Survey among developers for getting feedback
about the UCM2PCM tool
© ABB Group
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14. Evaluation
Tested Models
 Media Store
 Plain Java web application for storing and retrieving
media files.
 SPECjAppServer
 Industry-standard benchmark, designed to measure the
performance of application servers conforming to the
Java EE 5.0 or later specifications.
 Business Reporting System
 Loosely modeled after a management information
system, formerly analyzed at Carlton University. Users
can retrieve live business data from the system and run
statistical analyses.
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15. Evaluation
Business Reporting System UCM
© ABB Group
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16. Evaluation
Accuracy: Original vs. transformed UCM model
 Transformation successfully bridged
gap between UCM and PCM
 Simulation result difference to
reference model below 15% and
below 5% in most cases
 Accuracy is seen sufficiently for
early reasoning of different design
alternatives
© ABB Group
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17. Evaluation
Usability: qualitative user survey
 Main Advantages
 Comprehensibility of
model is high, also for
non-experts
 Fast(er) modeling
 Modeling complex
systems is seen critical
with UCM2PCM
 Results are only hints,
without statistical
relevance
© ABB Group
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18. UCM2PCM
Conclusions and Future Work
 Transformation successfully bridges
semantic gap between UCM & PCM
 High result accuracy
 Mainly positive feedback by survey
 Future Work
 Adding Input Assistance
to UCM editor
 Reverse transformation
from PCM to UCM
 Conducting further
case studies & experiments
© ABB Group
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19. © ABB Group
April 25, 2013 | Slide 19