Systematic Integration between Requirements and Architecture

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Systematic Integration between Requirements and
Architecture

• Lucia Bastos Jaelson Castro

Banco do Brasil S.A.
Centro de Informática UF Tecnologia
Universidade Federal de
Pernambuco UFPE Brasília, DF,
Brazil Recife,
Brazil
May, 2004
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Contents

• Motivation
• Role Theory and Organizational Structure
• Tropos Project
• The SIRA Framework
• SIRA Elements
• SIRA Process
• Final Considerations and Future Works

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Motivation
Index

• Semantic Gap among Requirements and Architecture
• Requirements are derived from concepts and
  relationships in the problem domain (for example,
  e-commerce, bank accounting) and architecture
  models are solution for the problem described in
  the requirements
• This conceptual differences between what to do
  (requirements) versus how to do (architecture)
  is one of the challenging problem in software
  engineering
• Goal-based Organizational Models
• Goals can be related to functional abilities,
  business and system qualities
• Goals can be used as starting point to construct
  the architectural description

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Contents

• Motivation
• Role Theory and Organizational Structure
• Tropos Project
• The SIRA Framework
• SIRA Elements
• SIRA Process
• Final Considerations and Future Works

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Role Theory and Organizational Structures
Index

• The Role Theory applied for enterprise modeling
• Individuals occupy positions in an organizations
• Associated to each position is a set of
  activities that constitute the responsibilities
  of that positions
• A organizational structure can define the roles
  of various components (actors), their
  responsibilities defined in terms of goals and
  tasks they have assigned and resources allocated
• Organizations consist of a collection of group
  (or a set of actors). A group represents a
  context of a role.
• The SIRA Framework uses the Role Theory concepts
• Software (i System actor) occupies a position
  that corresponds to a group (or a collection of
  sub-groups)

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Contents

• Motivation
• Role Theory and Organizational Structure
• Tropos Project
• The SIRA Framework
• SIRA Elements
• SIRA Process
• Final Considerations and Future Works

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Tropos Project
Index
Ontology
Actors, social dependencies, goals, resources,...
Application area
(Requirements-driven) Software development
Tropos, in Greek, means manner (as in manner
of doing things)
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Requirement Model Operational Context of the
System
Organizational Map

• Functions and qualities for the system within
  its environment

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Architectural Catalogue and Quality Attributes
Predictability, Security, Adaptability,
Cooperativity, Competitivity, Availability,
Integrity, Modularity, Aggregability
() contributes positively (very positively)
- (--) contributes negatively (very negatively)
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Contents

• Motivation
• Role Theory and Organizational Structure
• Tropos Project
• The SIRA Framework
• SIRA Elements
• SIRA Process
• Final Considerations and Future Works

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Proposal for Systematic Integration between
Requirements and Architecture
Index
The SIRA Framework
SIRA Elements
System Groups
Architectural Elements
Requirements model
SystemGroup schema
SIRA Process
Architectural model
Architectural catalogue
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SIRA Elements System Groups

• The software actors of the information system. A
  System Group can be a component or sub-components
  of a software system, like Medi_at_ actor to sell
  media items in Internet
• Each System Group can be refined into Sub Group
  to provide some service in a particular context
• System Roles Each Sub Group assume some
  behavior to execute a service in the context
• Responsibilities Services and capabilities
  assigned to a System Group or Sub-Group.
  Responsibility is extracted from the set of tasks
  to be performed and goals to be fulfilled by
  system actors, like Place order or Buy media
  items.

SIRA
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E-commerce Example System Group and
Responsibilities
System Group
Responsibilities (task and goal)
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SIRA Elements Architectural Elements

• The elements in architectural model.
• Components - System Actors (software elements)
  and Task/Goals/Resources dependencies between
  them
• Connectors, Protocols and Ports - A connector is
  an abstraction of a message-passing channel that
  connects two or more ports
• Constraints Assertions and constraints that
  apply to the entire software system. Many
  softgoals impose constraints on component
  interaction.

SIRA
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The SIRA Process
Index
Relating Elements
Analyzing Elements
Selecting Architecture
Requirements models, Architectural catalogue,
and SIRA Elements definition
System Group Schema and Architectural model
Architectural model
SIRA
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1 - Analyzing Elements

• This activity consist of analyzing the i
  elements (System actor) to identify an possible
  SIRA Element
• Three sub-activities
• Identify System Group
• Identify System Responsibilities
• Identify System Roles

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1.1 Identify System Group
Example
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1.2 Identify System Responsibilities
Responsibility Type
Example
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1.3 Identify System Roles
E-commerce Role Categorization
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The SIRA Process
Index
Relating Elements
Analyzing Elements
Selecting Architecture
Requirements models, Architectural catalogue,
and SIRA Elements definition
System Group Schema and Architectural model
Architectural model
SIRA
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2 Selecting Architecture

• This activity consist of selecting among
  alternative architectural styles
• Two sub-activities
• Identify the Architectural Constraints
• Each architecture must conform to the application
  domain qualities
• Apply NFR Framework
• Each architectural candidate will be analyzed
  based on positive contributions to priority
  qualities (constraints) of the application domain

Example
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2.1 - NFR Framework
From Security, Availability, Adaptability
() contributes positively (very positively)
- (--) contributes negatively (very negatively)
Selected Architecture - Joint Venture Style
NFR Table
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E-commerce Example System Group and Constraints
System Group
Constraints
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Selected Architecture - Joint Venture Style

• Based on a agreement between two or more
  principal partners.
• Principal Partner Autonomous on a local
  dimension and interacts directly with other
  principal partners to exchange services, data and
  knowledge
• Joint Management actor coordinates tasks and
  manages the sharing of knowledge and resources.
• Secondary Partners Supply services or support
  tasks for the organization core
• Joint Venture in i and UML

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Joint Venture in i and UML
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The SIRA Process
Index
Relating Elements
Analyzing Elements
Selecting Architecture
Requirements models, Architectural catalogue,
and SIRA Elements definition
System Group Schema and Architectural model
Architectural model
SIRA
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3 Relating SIRA Elements and Architectural
Elements

• This activity consist of deriving the
  relationship among SIRA elements and
  architectural elements. This relationship can be
  identified by Sub-Group Functionality and Roles.
• Three sub-activities
• Analyzing Architectural Components
• Identify Task/Goals/Resource Dependency between
  Sub-Groups
• Identify Architectural Connectors and Protocols
• E-commerce architecture

SIRA
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3.1 Analyzing Architectural Components
Medi_at_ Actor and Joint Venture components
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Joint-Venture E-commerce Architecture
Index
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Final Considerations Research contributions
Index

• Narrowing the gap among requirements gtlt
  architectures
• Requirement specification supported by a
  development methodology, the Tropos Methodology
• Using same concepts for requirements and
  architectures
• Social Groups, System Actors and roles
• Mapping requirements into architecture and
  maintaining consistency and traceability
• Refining requirement and architecture
  specifications into a systematic process

SIRA
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Future Works
Index

• Integration with some other Tropos Requirement
• Investigation of recent works in component-based
  approach
• Improve schemas, templates and guidelines
• Real study case to evaluate results

SIRA