Agenda

Goals

• Understand the ideas behind the UML meta‑model
• Using Profile Diagrams to customize UML for a domain

The UML Meta-Model

• UML Meta‑Model Basics
• Meta‑Model Architecture (MOF layers)
• How UML Constructs Are Defined

Profile Diagrams

• Profiles as Meta‑Model Customizations

1. What Is a Meta‑Model?

• A model represents a real‑world system.
• A meta‑model defines the rules for building models.
• UML itself is not just a set of diagrams — it is a modeling language defined by a meta‑model.

Key idea

The UML meta‑model defines:

• What a Class, Attribute, Operation, Association are
• How they relate
• What diagrams can contain

Model-Driven Architecture (MDA)

MDA is a software development approach defined by the Object Management Group (OMG)

• Focuses on creating and transforming models

  rather than writing code directly

• Separates business logic from platform-specific implementation

• Supports automation:

  models → transformations → generated code

Key MDA Model Types

CIM

Computation-Independent Model

(business/domain understanding)

PIM

Platform-Independent Model

(logic without tech details)

PSM

Platform-Specific Model

(technology-bound design)

Examples of MDA Languages / Modeling Standards

UML

Unified Modeling Language

(primary MDA modeling language)

MOF

Meta-Object Facility

(meta-modeling framework)

QVT

Query/View/Transformation

(model transformation language)

OCL

Object Constraint Language

(add constraints to models)

XMI

XML Metadata Interchange

(model serialization/exchange format)

2. The Meta-Object Facility (MOF) Architecture

UML is defined using a 4‑layer meta‑model architecture:

Visualization of the 4-layered MOF architecture for UML

Meta-Object Facility (MOF) in More Detail

• MOF is an Object Management Group (OMG) standard

• Defines how meta-models are built

• UML, SysML, BPMN meta-models are all built using MOF

• Enables interoperability between modeling tools

Key MOF Concepts

Classes

Meta-classes used to define modeling concepts (e.g., UML Class)

Properties

Define attributes and relationships in the meta-model

Packages

Group meta-model elements

Associations

Link meta-classes together

MOF Variants

Essential MOF (EMOF)

• A simplified subset of MOF
• Used for simple DSLs, transformation systems
  • Many DSLs (Domain-Specific Languages) use EMOF for simplicity

Complete MOF (CMOF)

• Offers the full expressive power of MOF
  • A particular aspect of CMOF is its Reflection layer
  • UML is defined in CMOF

Essential MOF (EMOF) classes

4. Profiles and Stereotypes (10 minutes)

Profiles are lightweight extensions to the UML meta‑model

• Add domain‑specific concepts
• Add constraints
• Specialize existing UML meta‑model elements
  • without modifying UML itself

Stereotypes extend UML elements

• Add tagged values
• Add constraints
• Add semantics

5. Profile Diagrams

Define UML extensions for domain-specific modeling.

• custom stereotypes, tagged values, and constraints.

5. Profile Diagram example

A profile diagram and a DSL model using it

Why Profiles instead of modifying the UML meta‑model?

• Profiles keep UML standard-compliant

• Tool‑friendly

• Tailored for specific domains

  (IoT, automotive, medical, cloud, finance)

Examples:

• SysML = UML Profile
• MARTE (real‑time systems) = UML Profile

Interactive exercise (Secure Web Services profile)

Create a UML Profile Diagram that extends UML to better describe security characteristics of web-service components.

Tasks

1. Create a WebSecurity profile
2. Add stereotypes
   1. SecureCompoent extends Component with encryption and CA tags
   2. SensitiveData extends Class with a dataCategory tag
   3. AuthRequired extends Operation with authLevel tag
3. Add at least one constraint
   • e.g., SensitiveData must have at least one private attribute

Summary

• UML is defined by a meta‑model (M2 layer) using MOF (M3 layer)

• Your diagrams are models (M1), representing real objects (M0)

• Profiles customize UML without altering the meta‑model

• Stereotypes add domain semantics and constraints

• Profiles are essential for domain‑specific modeling (e.g., SysML)