Nicolas Gorse

1
Participants and Collaborators

• Nicolas Gorse
• LOTOS Team
• SITE - School of Information
• Technology Engineering
• University of Ottawa

2
Objectives

• Specification Phase
• Feature Interaction avoidance and detection in
  early stages of development of a system.
• Improvement of the design/specification phase.
• Testing Phase
• Automatic generation of test suites.
• Reduction of the testing time and cost.

3
Main Ideas

• Specification Phase
• formulate logic specifications of features
• potential interactions will show as
  contradictions
• Testing Phase
• test cases are constructed from information on
  the contradictions found
• they will show if the potential interactions are
  real ones

4
FI Detection Using Predicate Logic, UCM and LOTOS
(contd)

• Derivation of a LOTOS specification from UCM (see
  companion project)
• Provides an executable model - prototype
• Provides information for scenario generation
• Scenario generation for possible interactions
  identified
• Using information on the structure of the feature
• Based on possible interactions identified

5
FI Detection Using Predicate Logic, UCM and LOTOS
(contd)

• Feature Interaction scenario-based validation of
  the LOTOS specification
• Allows to verify whether the possible
  interactions identified are present in the LOTOS
  spec
• Method only identifies possible interactions,
  however experimental study showed very high hit
  rate
• Scenarios derived can be reused at final system
  testing stage

6
Process Illustration
7
Process Illustration (contd)

• First identification of possible feature
  interactions and requirements improvement
• Graphical representation of the system
• Formal specification allowing to perform
  Scenario-based testing and model checking
• Generation of validation test suites
  Corresponding to the interactions identified
• Detection of FI in the LOTOS specification

8
Feature Interaction Filtering Using Predicate
Logic

• Representation of features
• Pre-conditions
• CFA subs(B, cfa), concerns(B, cfb), cfa(C)
• CFB subs(B, cfb), concerns(B, cfb), busy(A),
  cfb(D)
• Triggering Events
• CFA call(A, B) Same triggering events
• CFB call(A, B) for both features
• Results
• CFA call(A, C), connect(A, C) Different
  results,
• CFB call(A, D), connect(A, D) non determinism

9
Process Illustration
10
Lessons Learned

• Mitel project
• 22 feature descriptions (484 pairs), 4 users
• 43 possible interactions found in 84.14 secs
• Feature Interaction contest
• 97 feature descriptions (9409 pairs), 4 users
• 149 possible interactions found in 1299.93 secs
• Fairly quick representation of features
• Rapid method, accessible to non-specialists

11
Deliverables and Project Plan

• Achieved
• Method fully developed
• Master Thesis Submitted
• Future work
• Improvement of the method for detection of new
  kind of Feature Interactions
• Addition of a Graphical User Interface for the
  Design of features
• Distribution of the algorithm over a network

12
References

• Use Case Maps
• Various documents about Use Case Maps, UCM web
  site, http//www.usecasemaps.org/
• Feature Interactions
• K. Kimbler, L.G. Bouma, Feature Interactions in
  Telecommunication and Software Systems V, IOS
  Press, 1998
• M Calder, E.H. Magill, Feature Interactions in
  Telecommunication and Software Systems VI, IOS
  Press, 2000