A Practical Guide to SysML

Systems engineers and architects must understand how all the parts of a system work together to satisfy its requirements. SysML is a general purpose graphical modeling language used to specify, analyze, and design systems that may include hardware, software, and personnel. It allows engineers to describe how a system interacts with its environment, and how its parts must interact to achieve the desired system behavior and performance. The SysML model provides a shared view of the system, enabling a design team to surface issues early and prevent problems that would otherwise delay development and degrade design quality. Since SysML is based on UML, it also facilitates integration between systems and software development. SysML is now being adopted by companies across a broad range of industry, including Aerospace and Defense, Automotive, and IT System Developers.

This book provides a comprehensive and practical guide for modeling systems with SysML. It includes a full description of the language along with a quick reference guide, and shows how the language can be applied to specify, analyze, and design systems. It contains examples to help readers understand how SysML can be used in practice. The book also includes guidance on how an organization or project can transition to model based systems engineering using SysML, with considerations for processes, methods, tools, and training.

*The authoritative guide for understanding and applying SysML
*Authored by the foremost experts on the language
*Language description, examples, and quick reference guide included

Part I Introduction

1 Systems Engineering Overview

1.1 Motivation for Systems Engineering

1.2 The Systems Engineering Process

1.3 Typical Application of the Systems Engineering Process

1.4 Multi-Disciplinary Systems Engineering Team

1.5 Codifying Systems Engineering Practice through Standards

1.6 Summary

1.7 Questions


2 Model-Based Systems Engineering

2.1 Contrasting the Document-Based and Model-Based Approach

2.2 Modeling Principles

2.3 Summary

2.4 Questions


3 SysML Language Overview

3.1 SysML Purpose and Key Features

3.2 SysML Diagrams Overview

3.3 Using SysML in Support of MBSE

3.4 A Simple Example Using SysML for an Automobile Design

3.5 Summary

3.6 Questions


Part II Language Description

4. SysML Language Architecture

4.1 The OMG SysML Language Specification

4.2 The Architecture of the SysML Language

4.3 SysML Diagrams

4.4 The Surveillance System Case Study

4.5 Chapter Organization for Part II

4.6 Questions


5 Organizing the Model with Packages

5.1 Overview

5.2 The Package Diagram

5.3 Defining Packages Using a Package Diagram

5.4 Organizing a Package Hierarchy

5.5 Showing Packageable Elements on a Package Diagram

5.6 Packages as Namespaces

5.7 Importing Model Elements into Packages

5.8 Showing Dependencies Between Packageable Elements

5.9 Specifying Views and Viewpoints

5.10 Summary

5.11 Questions


6 Modeling Structure with Blocks

6.1 Overview

6.2 Modeling Blocks on a Block Definition Diagram

6.3 Modeling the Structure and Characteristics of Blocks Using Properties

6.4 Modeling Block Interfaces Using Ports and Flows

6.5 Modeling Block Behavior

6.6 Modeling Classification Hierarchies Using Generalization

6.7 Summary

6.8 Questions


7 Modeling Constraints with Parametrics

7.1 Overview

7.2 Using Constraint Expressions to Represent System Constraints

7.3 Encapsulating Constraints in Constraint Blocks to Enable Reuse

7.4 Using Composition to Build Complex Constraint Blocks

7.5 Using a Parametric Diagram to Bind Parameters of Constraint Blocks

7.6 Constraining Value Properties of a Block

7.7 Capturing Values in Block Configurations

7.8 Constraining Time-Dependent Properties to Facilitate Time-Based Analysis

7.9 Using Constraint Blocks to Constrain Item Flows

7.10 Describing an Analysis Context

7.11 Modeling Evaluation of Alternatives and Trade Studies

7.12 Summary

7.13 Questions


8 Modeling Flow-Based Behavior with Activities

8.1 Overview

8.2 The Activity Diagram

8.3 Actions-The Foundation of Activities

8.4 The Basics of Modeling Activities

8.5 Using Object Flows to Describe the Flow of Items Between Actions

8.6 Using Control Flows to Specify the Order of Action Execution

8.7 Handling Signals and Other Events

8.8 Advanced Activity Modeling

8.9 Relating Activities to Blocks and Other Behaviors

8.10 Modeling Activity Hierarchies using Block Definition Diagrams

8.11 Enhanced Functional Flow Block Diagram (EFFBD)

8.12 Executing Activities

8.13 Summary

8.14 Questions


9 Modeling Message-Based Behavior with Interactions

9.1. Overview

9.2. The Sequence Diagram

9.3. The Context for Interactions

9.4. Using Lifelines to Represent Participants in an Interaction

9.5. Exchanging Messages Between Lifelines

9.6. Representing Time on a Sequence Diagram

9.7. Describing Complex Scenarios Using Combined Fragments

9.8. Using Interaction References to Structure Complex Interactions

9.9. Decomposing Lifelines to Represent Internal Behavior

9.10. Summary

9.11. Questions


10 Modeling Event-Based Behavior with State Machines

10.1 Overview

10.2 State Machine Diagram

10.3 Specifying States in a State Machine

10.4 Transitioning Between States

10.5 State Machines and Operation Calls

10.6 State Hierarchies

10.7 Contrasting Discrete versus Continuous States

10.8 Summary

10.9 Questions


11 Modeling Functionality with Use Cases

11.1 Overview

11.2 Use Case Diagram

11.3 Using Actors to Represent the Users of a System

11.4 Using Use Cases to Describe System Functionality

11.5 Elaborating Use Cases with Behaviors

11.6 Summary

11.7 Questions



12. Modeling Text-Based Requirements and Their Relationship to Design

12.1 Overview

12.2 Requirement Diagrams

12.3 Representing a Text Requirement in the Model

12.4 Types of Requirements Relationships

12.5 Representing Cross-Cutting Relationships in SysML Diagrams

12.6 Depicting Rationale for Requirement Relationships

12.7 Depicting Requirements and Their Relationships in Tables

12.8 Modeling Requirement Hierarchies in Packages

12.9 Modeling a Requirements Containment Hierarchy

12.10 Modeling Requirement Derivation

12.11 Asserting a Requirement Is Satisfied

12.12 Verifying that a Requirement Is Satisfied

12.13 Reducing Requirements Ambiguity Using the Refine Relationship

12.14 Using the General-Purpose Trace Relationship

12.15 Summary

12.16 Questions


13. Modeling Cross-Cutting Relationships with Allocations

13.1 Overview

13.2 Allocation Relationship

13.3 Allocation Notation

13.4 Types of Allocation

13.5 Planning for Reuse: Specifying Definition and Usage in Allocation

13.6 Allocating Behavior to Structure Using Functional Allocation

13.7 Connecting Functional Flow with Structural Flow Using Functional Flow Allocation

13.8 Modeling Allocation Between Independent Structural Hierarchies

13.9 Modeling Structural Flow Allocation

13.10 Evaluating Allocation Across a User Model

13.11 Taking Allocation to the Next Step

13.12 Summary

13.13 Questions


14 Customizing SysML for Specific Domains

14.1 Overview

14.2 Defining Model Libraries to Provide Reusable Constructs

14.3 Defining Stereotypes to Extend Existing SysML Concepts

14.4 Extending the SysML Language Using Profiles

14.5 Applying Profiles to User Models in Order to Use Stereotypes

14.6 Applying Stereotypes When Building a Model

14.7 Summary

14.8 Questions


PartIII Modeling Examples

15 Water Distiller Example Using Functional Analysis

15.1 Stating the Problem

15.2 Defining the Model-Based Systems Engineering Approach

15.3 Organizing the Model

15.4 Establishing Requirements

15.5 Modeling Behavior

15.6 Modeling Structure

15.7 Analyzing Peformance

15.8 Modifying the Original Design

15.9 Summary

15.10 Questions


16. Residential Security System Example Using the Object-Oriented Systems Engineering Method (OOSEM)

16.1 Method Overview

16.2 Residential Security Example Overview and Project Setup

16.3 Applying the Method to Specify and Design the System

16.4 Summary

16.5 Questions


Part IV Transitioning to Model-Based Systems Engineering

17. Integrating SysML into a Systems Development Environment

17.1 Understanding System Model's Role in a Systems Development Environment

17.2 Integrating the System Modeling Tool with Other Tools

17.3 Data Exchange Mechanisms in an Integrated Systems Development Environment

17.4 Selecting a System Modeling Tool

17.5 Summary

17.6 Questions


18. Deploying SysML into an Organization

18.1 Improvement Process

18.2 Summary

18.3 Questions