Design and Implementation of a Rationale-Based Analysis
Tool (RAT)
Diploma thesis from Timo Wolf
Design and Realization
of a Tool for Linking Source Code
and Rationale Knowledge
Diploma thesis from Marc Mährländer
Content
• Introduction
– What is Rationale?
– Problem – Solution
– Scope of the works
• Rationale Support
• RAT
• SourceQuest (JBuilder plug-in)
• Demonstration
What is Rationale?
• The why behind a decision
– Discussion that leads to a solution – Alternative solutions
– The criteria the alternatives have been evaluated against.
– Trade-offs made by the stakeholders
• Rationale contains useful information
• Historically, often called Design Rationale
Problem Statement
• During all phases of development, many issues have to be solved
– Normally, only the selected solution is visible in the work products
– Useful rationale information get lost
• Discussion process is not structured
– Face-to-face meetings, e-mail, bboards, ...
– Not integrated into today‘s development tools
• Natural documentation problem
– Designing and implementing is the interesting part, documentation is without a great personal benefit
Solution
• Full integration of rationale into the complete development process
– All development tools need integrated support for rationale
– Creation of a direct effort for the developers,
because of a structured and integrated discussion process
– Developers coming after, profit from the rationale information
Focusing on issues, and making the discussion process transparent and explicit, improves the quality of the decisions made by the developers.
Focusing on issues, and making the discussion process transparent and explicit, improves the quality of the decisions made by the developers.
Issue-based Life Cycle Model
• Complete life cycle model for software development based on issues
– Rationale is not only integrated into the development process
– Rationale becomes the structuring element of a software project
• Each project starts with a set of issues
– Issues can be mapped to certain phases of the process
– The status of issues can then be used to track and control the status of each activity
Scope of the Works
Requirement Elicitation/
Analysis
System Design
Object Design
Implementation Rationale Management
...
...
Development support services
RAT JBuilder/
SourceQuestRationale Manager
Awareness Support
Notification Service
...
Development tools
Development activities
Rationale Support
Scope of Marc‘s Work
• Integrating rationale support into a source code editor (called SourceQuest)
• Providing a component to store references between different kinds of objects
(LinkingService)
– Links rationale information to model objects.
• Providing a Rationale Manager software
Rationale Support
Content
• Introduction
• Rationale Support
– Requirements for Rationale support – Rationale Model
– Actors
– Rationale Manager
• RAT
• SourceQuest (JBuilder plug-in)
• Demonstration
Requirements for Rationale Support
• Create and navigate references between model objects and rationale information
– A model object may have different representations
Model Objects
Model Object Model Object
Class
Class PackagePackage Use CaseUse Case ...
Concrete Representation
Concrete Representation
Java Source File
Java Source File
UML Class UML Class
0..*
Requirements for Rationale Support
• Create and navigate references between model objects and rationale information
– A model object may have different representations
• Restructuring of captured rationale information
– Remove elements
– Combining and dividing issues – Create missing references
• Querying the rationale information
Rationale Model
Issue Issue
Option Option
0..*
Criterion Criterion
Comment Comment
responds-to
is relevant
assessment
Actors
• Developer
– Creates rationale information related to model objects
– Uses rationale information
– Rationale integration supports his main tasks
• Rationale Maintainer
– Restructures rationale information – Identifies missing rationale
Rationale Manager
• Supports the user tasks of the Rationale Maintainer
– Displaying issues – Restructuring issues
– Querying and searching rationale information
• Provides a UI to access rationale information, which can be integrated into development
tools.
Rationale Manager
Rationale Manager
Design and Implementation of a Rationale-Based Analysis Tool
(RAT)
Diploma thesis from Timo Wolf
Content
• Introduction
• Rationale Support
• RAT
– Analysis activities – Goals
– Constraints
– Components RAT has to deal with – Architecture
– Evaluation
– Future Directions
• SourceQuest (JBuilder plug-in)
• Demonstration
Analysis activities
Define use case
Define participating
objects
Review model Define interactions
Define objects
types
Define attributes
Define associations
Consolidate model
Goals
• RAT supports developers during analysis activities
• Enables developers to define use cases, sequence diagrams and classes
• No assumption about any specific order
– e.g., instances may be created before classes
• Sequence diagrams must be easy to draw
– e.g., not like Together or Rose, where it takes a lot of effort to redraw and layout
• RAT supports rationale management
• RAT supports multiple concurrent users
Constraints
• Software Engineering Prakitkum
• Must integrate with other tools in the practical course
– REQuest
– SourceQuest
– Rationale-Manager
– All tools must share the same issue repository – All tools must provide a consistent interface
• Must be portable across OS
– (Mac OS X, Windows, Linux)
Components RAT has to deal with
• Use Cases
RAT‘s Use Cases
– Use cases – Actors
– Services
– Flow steps (actor step, system step)
UML use case diagram
Components RAT has to deal with
• Classes
RAT‘s Class Model
Tree view
UML Class Diagram
Detailed element
interaction window
Components RAT has to deal with
• Sequence Diagrams
RAT‘s Sequence Diagrams
UML sequence diagram
RAT‘s Sequence Diagrams
Sharing objects and messages among multiple diagrams
Components RAT has to deal with
• Rationale Management
Rationale in RAT
•Defining issues to all elements of RAT
•Issue highlighting in RAT
•Navigation from elements to issues
Visualisation of issues by using the Rationale-Manager of SourceQuest
Relations among RAT‘s models
Class Object
Operation
Message Actor
Service
FlowStep SDModel
UseCase
0..1 0..1
0..*
0..1
0..1 0..*
0..1 0..1
0..*
0..1
0..1 0..1
0..1 0..*
1 0..*
0..*
2
Architecture
• Central repository architecture (server)
• Repository is used for models and issues
• Concurrent distributed client applications
• Separation of the linking repository
• Implementation in Java
– Platform independence
• Event-driven control flow (using Java Remote
Method Invocation, RMI)
Hardware/Software Mapping
:Webserver REQuest :central repository
ElementStore
LinkingService :SourceQuest user computer
SourceQuest
:RAT user computer
Rationale Manager
RAT Application
Evaluation
• How much of it works ?
– All basic functionality works
• What needs to be improved ?
– Performance for low bandwidth connections – Some sequence diagram functionalities,
e.g., hiding messages.
• What is missing ?
– User management system
Future Directions
• Evaluation of RAT in the practical course
• Full REQuest integration
• Integration with the Chair's User Management
• Automatic diagram layout functionality
• Integrating RAT with rationale-based system
and object design tools (to be developed)
SourceQuest
JBuilder Rationale Plug-In
Content
• Introduction
• Rationale Support
• RAT
• SourceQuest (JBuilder plug-in)
– Requirements – User Interface – Evaluation
• Demonstration
Requirements
• Users must become aware of existing issues related to the class they are working on
• Users must be able to create new issues related to the current class
• Users must be able to browse issues related to their current class
• As easy to use as possible
• Smooth integration of rationale support into
JBuilder
User Interface I
User Interface II
User Interface III
Evaluation
• Must be evaluated in real projects
• First project
– usability?, developers acceptance?,
understandability of the rationale model?, what kind of training is necessary?, can all rationale information be expressed?, is decision quality increased
• Second project
– Evaluate the value of rationale information
– is rationale information used?, can it be found?, is time for working in decreased?, is quality
increased?
