Budapest University of Technology and Economics Department of Measurement and Information Systems

Modeling Requirements, Architectures, Behaviour ...

The System Modeling Language (SysML) and the SYSMOD modeling approach

Acknowledgement

Portions of this presentation are from

o Systems Engineering with SysML/UML, by Tim Weilkiens, published by Morgan Kaufmann Publishers, Copyright 2007 Elsevier Inc. All rights reserved.

o A Practical Guide to SysML, by Sanford Friedenthal, Alan Moore, and Rick Steiner, published by Morgan Kaufmann Publishers, Copyright 2009 Elsevier Inc. All rights reserved.

o IBM course, Requirements management

2

Overview

Context

SysML Overview

SysML details + the SYSMOD Systems Engineering Methodology

3

Systems Engineering Systems Engineering is a multidisciplinary approach to

develop balanced system solutions in response to diverse stakeholder needs

~ Integration Engineering o Software engineering o Hardware engineering o Mechanical engineering o Safety engineering o Security engineering o ...

~ Process Engineering System

o Military, airplane, car, aviation, railway interlocking, notebook, etc.

4

Systems Engineering Process

V-model

5

V-model – v2

6

EN50129

7

Vision

Acceptance Tests Stakeholder

Requirements

Operational Use

System Tests System

Requirements

Component Tests Component

Requirements

V-model – v3

Pro

ble

m

Sp

ace

So

lutio

n S

pa

ce

8

Stakeholder requirements

• A description of the problem

and its context

• Describes what stakeholders

want from the system

• Not the definition of the solution

(except for environment)

• Quality of results

• Created by stakeholders

System requirements

• An abstract representation of

the solution

• Describes what the system

will do

• Not the definition of the

design

• How well it does it

• Created by systems

engineers

“The user shall be able to ....” “The system shall do ….”

Differentiating Problem and Solution

Problem Solution

9

analyze

& model

derive

requirements

and acceptance

strategy

Models

Acceptance Strategy Output Specification

agree

with

supplier

Input Specification

agree

with

customer

Acceptance Strategy

Request Change

Request Change

Request Change

10

Vision

Acceptance Tests Stakeholder

Requirements

Operational Use

System Tests System Requirements

Component Tests Component

Requirements

11

Functional modeling

Functional modeling

Functional modeling

Models Bridge Layers of Requirements

e.g Goal / Usage modeling

e.g. Functional modeling

Stakeholder Requirements

Subsystem Requirements

System Requirements

Vision

e.g. Performance modeling

Importance of Traceability

12

Vision

Acceptance Strategy Stakeholder

Requirements

Operational Use

System Test System Requirements

Acceptance Strategy Architecture

Validating the product

Accepting the product

Verifying the product

Evaluating subsystems

satisfies

satisfies

satisfies

Impact Analysis

Importance of Traceability

13

Vision

Acceptance Strategy Stakeholder

Requirements

Operational Use

System Test System Requirements

Acceptance Strategy Architecture

satisfies

satisfies

satisfies

?

?

Coverage analysis

Overview

Context

SysML Overview

SysML details + the SYSMOD Systems Engineering Methodology

14

SysML overview

„UML for Systems Engineering” o Supports the specification, analysis, design, verification

and validation of systems that include hardware, software, data, personnel, procedures, and facilities

Developed by OMG and International Council on Systems Engineering (INCOSE)

OMG SysML™ (http://www.omgsysml.org) o RFP – March 2003

o Version 1.0 – September 2007

o Version 1.1 – November 2008

o Version 1.2 – June 2010

o Version 1.3 – June 2012

15

Relationship Between SysML and UML

UML 2

UML 2

Reuse

(1, 2)

UML

reused by

SysML

UML

not required

by SysML

(UML -

UML4SysML)

SysML

extensions to

UML

SysML

16

UML4SysML

SysML Profile

SysML Diagram Taxonomy

17

Aspects of SysML

18

Overview

Context

SysML Overview

SysML details + the SYSMOD Systems Engineering Methodology

19

Language vs. Methodology

Modeling Language

o Defines elements and their relationship

o Defines syntax and semantics

o What type of elements can be used during modeling?

o E.g. SysML

Development Methodology

o Defines the steps of analyzing and designing the system

o Defines the usage of the model elements and diagrams

o How shall the model be built?

o E.g. SYSMOD (SYStem MODeling) by Tim Weilkiens

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The SYSMOD approach

Analyzing Requirements

21

The SYSMOD approach for design

22

SysML

Represents behavior in terms of the ordering of actions based on the availability of inputs, outputs, and control, and how the actions transform the inputs to outputs

23

Activity diagram

Name of activity

Action in activity

Pin

Object

Parameter of activity

Object flow

Describe Project Context

Car rental system o Works without staff

• Customer identification needed

o Central computer in radio compartment • Communicates with central

reservation system

• Collects usage data

• Comfort features – Navigation

– Radio

– Phone

– ...

24

Determine requirements

25

Identify stakeholders

26

Identify stakeholders

27

Collect requirements

28

SysML

Requirements diagram Represents text-based requirements and their relationship with other requirements, design elements, and test cases to support requirements traceability

29

Requirements diagram

Type of context element

Name of context element

Name of diagram

Requirement

Requirement composition

Collect requirements

30

Model System Context

31

Identify System Actors

32

SysML

33

Block Definition Diagram Represents structural elements called blocks, and their composition and classification

Block definition diagram

Block Actor

Model System-Actor Information Flow

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Identify System Interaction Points

35

System Context

36

Model Use Cases

38

Model Use Cases

39

SysML

40

Use Case Diagram Represents functionality in terms of how a system or other entity is used by external entities (i.e., actors) to accomplish a set of goals

Use case diagram

Use case

Actor Object flow

Model Use Cases

Organizing use cases into packages

41

SysML

Requirements traceability

42

Describe Use Cases Essences

43

Describe Use Cases Essences

44

Describe Use Cases Essences

45

Model Use Case Flows

46

Model Object Flows

47

Model Domain Knowledge

48

Create Glossary

49

Supports better understanding

The SYSMOD approach for design

50

Model System/Actor Interaction

51

SysML

52

Sequence Diagram Represents behavior in terms of a sequence of messages exchanged between parts

Sequence diagram

Derive System Interfaces

53

Model System Structures

54

Identify system components

Model System Structures

55

Identify relation of components

SysML

56

Internal Block Diagram Represents interconnection and interfaces between the parts of a block

Internal block diagram

Part: usage of block type

Flow port

Standard port

Interfaces

Item flow

Model System Structures

57

Structural allocation

Model System Structures

58

Functional allocation:

Actions to System components

Model System Structures

59

Traceability to requirements:

Blocks satisfying a req.

Derive State Model

60

Derive State Model

61

SysML

62

State Machine Diagram Represents behavior of an entity in terms of its transitions between states triggered by events

Parametrics

Constraints on block properties

66

SysML

67

Parametric Diagram Represents constraints on property values used to support engineering analysis

Parametric diagram

Constraint property node

Block value Value binding

Variant Management

68