Sequence Diagram

Definition

A sequence diagram is a bottom-level requirement diagram work product that primarily documents the interactions between classes and types (interfaces) of objects.

Objectives

The typical objectives of a sequence diagram is to:

• Document the essential classes and types (interfaces) of business objects.

Benefits

The typical benefits of a sequence diagram are to:

• It provides a more formal definition to the business terms defined in the glossary.

Contents

The typical contents of a sequence diagram are:

• Classes of business objects.
• Types of business objects.
• Optionally their attributes and operations.
• Referential relationships between them.
• Definitional relationships between them.

Stakeholders

The typical stakeholders of a sequence diagram are:

• Producers:
  • Software Development Team
• Evaluators:
  • Project Manager
  • Technical Leader
• Approvers:
  • Project Manager
  • Technical Leader
  • Customer Representative
• Maintainers:
  • Software Development Team
• Users:
  • Software Development Team

Phases

• Business Strategy: Completed
• Business Optimization: Not Applicable
• Initiation: Completed
• Construction: Maintained
• Delivery: Maintained
• Usage: Maintained
• Retirement: Archived

Preconditions

Sequence diagrams can typially be started if the following preconditions hold:

• The initiation phase has started.
• The requirements team is adequately staffed and trained in requirements analysis.

Inputs

The typical inputs to a sequence diagram include:

• Work Products:
  • Application Vision Statement
• Stakeholders:
  • TBD

Guidelines

• TBD

Conventions

Sequence diagrams are typically constrained by the following conventions:

• Work Flow
• Content and Format Standard
• Inspection Checklist

Examples

• Example Sequence Diagram