mbse extravaganza experience and application of mbse · platform n platform 1 code/obj test data...

© 2019. Changan UK R&D Centre Limited. Copyright © (2019) by (Andy Howells). Published and used by Scarecrow Ltd with permission.

MBSE Extravaganza Experience and Application of MBSE

Changan UK R&D Centre

Andy Howells – Head of Powertrain Control and Electronics

February 2019

Context – Three-plus-two Packages

Copyright © 2018 2

ImplementationApproach System

Process Set

Tool

Visualisation

Framework

Ontology Viewpoint

ModelSystem

View

Notation

Diagram

Compliance

Standard

1..*

1..*

implements

1..*

1

abstracts

1..*

1..*complies with

1..*

1

is consistentwith

1..*

1 1..*

1..*

complies with

1..*

1..*

visualises

1

1..*

is based on

1

1..*

implements

1..*

1..*describes how

to use1..*

1

is consistentwith

1..*

1

defines templatefor

1..*

1..*

Context – Evolution

Copyright © 2019 3

Stage 1: Document-

based

Stage 2: Document-

centric

Stage 3: Model-

enhanced

Stage 4: Model-centric

Stage 5: Model-based

© 2019. Changan UK R&D Centre Limited. Copyright © (2019) by (Andy Howells). Published and used by Scarecrow Ltd with permission 4

1. Introduction and Experiences

2. MBSE in Context

3. Bringing Everything Together – Example

4. MBSE Considerations and Issues

5. Summary


Introduction

30th Year in Engineering

Joined INCOSE in 1995

Passion for System Engineering

“Develop Complex Systems as simply and efficiently as possible”

Experiences

Education

Knowledge

Training

Application

Mentoring


13 Years

CONTEXT Post Cold War “Option for Change”

• Capability Development

• Better equipped smaller forces

• A drive to reduce Procurement costs with better Systems Engineering application?

Key Experiences BEng. Sponsorship, Variety, experience, importance

of mentoring and quality training

DOORS – Doesn’t make you a Requirements Engineer.

It’s all about the end user – Reliable and Simple

Functional based Textual based requirements are hard to get right

MODAF - View Points and Architecture Frameworks the Future?

Experience Summary

© 2019. Changan UK R&D Centre Limited. Copyright © (2019) by (Andy Howells). Published and used by Scarecrow Ltd with permission

11 Years

7

Interface

management

Interface

management

•System Arch. Analysis

•Derive Sub-system Options

•Sub-system Trade Studies

•Sub-system Analysis

•Enterprise Analysis

•System of Systems

•Stakeholder Analysis

•Context System Analysis

•Use Case Analysis

•System Trade Studies

•Behaviour Analysis

•Physical Analysis

• Functional Analysis

D O D A F

User

Requirement

s

User

Requirement

s

Con

Ops

Con

Ops

System

Requirement

s

System

Requirement

s

Subsystem

Specs

Subsystem

Specs

Validation

Strategy

Validation

Strategy

Reference

Model

Reference

Model

Algorithm

Spec

Algorithm

Spec

•Sub-system Development

•Software Design

•Hardware Design

• Integration

• Trials

Software

Code

Software

Code

HardwareHardware

Activities

Outputs

System

Architecture

Model

ALGO

MODEL

(MATLAB SIMULINK)

PERFORMANCE

MODEL

(MATLAB SIMULINK,

SME TOOLS)

S/W REALISATION

MODEL (UML)

SOFTWARE

TESTING

MODEL (UML)

PIM

PLATFORM n

PLATFORM 1

Code/Obj

Test Data

Reusable Components

Design Patterns

Code Insert for

Performance Model

ALGO

MODEL

(MATLAB SIMULINK)

PERFORMANCE

MODEL

(MATLAB SIMULINK,

SME TOOLS)

S/W REALISATION

MODEL (UML)

SOFTWARE

TESTING

MODEL (UML)

PIM

PLATFORM n

PLATFORM 1

Code/Obj

Test Data

Reusable Components

Design Patterns

Code Insert for

Performance Model

D O D A F

Enterprise

Model

Sub-System

Model

MBSE

MBSE/

MDA

MDA

Interface

management

Interface

management

•System Arch. Analysis

•Derive Sub-system Options

•Sub-system Trade Studies

•Sub-system Analysis

•Enterprise Analysis

•System of Systems

•Stakeholder Analysis

•Context System Analysis

•Use Case Analysis

•System Trade Studies

•Behaviour Analysis

•Physical Analysis

• Functional Analysis

D O D A FD O D A F

User

Requirement

s

User

Requirement

s

Con

Ops

Con

Ops

System

Requirement

s

System

Requirement

s

Subsystem

Specs

Subsystem

Specs

Validation

Strategy

Validation

Strategy

Reference

Model

Reference

Model

Algorithm

Spec

Algorithm

Spec

•Sub-system Development

•Software Design

•Hardware Design

• Integration

• Trials

Software

Code

Software

Code

HardwareHardware

Activities

Outputs

System

Architecture

Model

ALGO

MODEL

(MATLAB SIMULINK)

PERFORMANCE

MODEL

(MATLAB SIMULINK,

SME TOOLS)

S/W REALISATION

MODEL (UML)

SOFTWARE

TESTING

MODEL (UML)

PIM

PLATFORM n

PLATFORM 1

Code/Obj

Test Data

Reusable Components

Design Patterns

Code Insert for

Performance Model

ALGO

MODEL

(MATLAB SIMULINK)

PERFORMANCE

MODEL

(MATLAB SIMULINK,

SME TOOLS)

S/W REALISATION

MODEL (UML)

SOFTWARE

TESTING

MODEL (UML)

PIM

PLATFORM n

PLATFORM 1

Code/Obj

Test Data

Reusable Components

Design Patterns

Code Insert for

Performance Model

D O D A FD O D A F

Enterprise

Model

Sub-System

Model

MBSE

MBSE/

MDA

MDA

Experience Summary

CONTEXT Reduce costs and Quicker to Market

System Complexity Increasing

International Collaboration

Convergence and modern practices in engineering methods & tools

• Systems & Software convergence (SysML and UML)

• Electronics & Mechanical treated as part of the system (SysML supports this!)

Key Experiences

System Design/Architect Lead – key role!

International Team work and Collaboration: Diagrams are much easier to share and understand.

Progressive introduction of SE and MBSE

Senior Management Sponsorship and Patience – no overnight solutions!

http://www.armedforces.co.uk/raf/listings/raf8e1.htm

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6 Years

8

CONTEXT Chinese Automotive Company

Move to develop own products using 7 Research and Development centres

Changan UK Focus on developing homegrown Powertrains

“Green Field” site for Engineering capability

Drive for Energy Efficiency and Low Emission

Key Experiences Started with very little infrastructure

Built a team, design/deliver products and build capability at the same time!

Understand the problem space – gather data and facts!

System Engineering and Model Based System Engineering (MBSE) – initial focus on control systems

Development of Capability Pyramids

Experience Summary

Context – Evolution

Copyright © 2019 9

Stage 1: Document-

based

Stage 2: Document-

centric

Stage 3: Model-

enhanced

Stage 4: Model-centric

Stage 5: Model-based


MBSE Journey at Changan


• Traditionally used in Aerospace, Defence and Nuclear Industries, the automotive industry are now becoming more aware of the importance of defining a system architecture

• Means of defining a system from a number of perspectives and levels of abstraction is becoming essential!

• Architecture Frameworks such as AUTOSAR are being devised to provide standardised descriptions of automobile systems.

• To understand how systems work together to deliver functionality

• To be able to join up systems into “systems of systems”

• Model Based System Engineering (MBSE) utilising System Modelling Language (SysML) is becoming a standard language for defining Systems

• A common language to describe systems

• To enable re-use of system and software components

• Computer-Aided Systems Engineering (CASE) tools for system analysis and design are becoming more powerful and mature

• E.g. IBM Rhapsody, Artisan Studio, Enterprise Architect, Magic Draw

Automotive Industry and System Engineering


My Job Spec (2013)

12

Key Challenge: To develop a highly complex hybrid Powertrain in a multinational environment The need for effective collaboration The management of engineering complexity How to Introduce and develop the use of System

Engineering Ensure we consider modularity and re-use

Improve the quality of Changan products

Key Challenge: Development of a highly complex product in a multi-national environment.

The Challenge


Historically Changan commit most resources during Product Realisation and Production phases. Observations:

• Concept phases based on competitors or existing designs;

• Engineering focus on Physical rather than functional design;

• Lack of formal requirements; • Too many Technical Issues found

during Production and Test; • Lack of “System” Thinking.

Focusing on good System Engineering principles including Requirements and Design were seen as key enablers.

Problems and Challenges (2013)

Initial Analysis and Benchmark


1st Introduction to MBSE (2014)

14

“Didn’t tell anyone that I was using MBSE – Very simple training/facilitation required. Didn’t worry too much about SysML compliance”

• Used as a basis for me to learn about advanced Powertrains and how they work!

• Most work undertaken on Whiteboards • results captured in toolset later.

• Used simple Use Case Analysis as an introduction

• Simple templates with a focus on making sure the whole project team had a common understanding of how the system should behave!

• Common Item Definition boundary diagrams

• A common diagram that has a common understanding of the physical architecture and system/sub-system names and structure.

1st MBSE Application


Basic MBSE Results and Benefits (2014)

15

“The MBSE approach deployed on the project has already realised significant benefits and reduced technical risks “ Vice President Changan

• Basic Use Case Analysis completed • Observations against Traditional Projects:

Common Understanding Complexity Managed Improved Collaboration

Structured and clearer

Requirements Issues found Earlier

1st MBSE Application


MBSE/SE Implementation Strategy

16

CAUK key SE/MBSE Implementation Strategy: • Gain sponsorship from Changan

senior management • Set up a well-funded capability

team focusing on System Engineering improvement

• Phased introduction approach with carefully selected external support

• Document Process, methods and tools (ongoing)

Changan UK strategy will focus on People First then Infrastructure, Process and finally Tools

© 2019. Changan UK R&D Centre Limited. Copyright © (2019) by (Andy Howells). Published and used by Scarecrow Ltd with permission 17 17

Sponsorship Disciples and Islands Leadership and Mindfulness Recognition of Challenge Mentoring and Architects System Thinking Competency Development Expert Help

MBSE Graphical Based Design approach

Approach to Context based Requirements Engineering (ACRE)

AUTOSPICE Scalable Ontology development System and Software Architectures

Whiteboards! Infrastructure and toolset capability Phased Introduction Collaborative Environments Toolset aligns with our Process, Method

and People needs Good Quality Output

Capability Pyramid - Strategy


What is MBSE?

Use of Diagrams rather than Words! Provides an approach for designing the system

The system is designed in levels The higher level design provides the context for the next level down

The requirements at each level come from the higher level context Different stakeholders have different perspectives on the system at each level Each perspective has needs of the system that are translated into requirements

Provides context for the system requirements Helps validate that they are complete and testable

Emphasises the importance of making the system design visible The evolving design is defined in a standardised way throughout the development using a model Enabling the expression of required system behaviour at each level Enabling definition of the designed system functions and structure including its interfaces

Facilitates design of modular systems and re-use of components True model-based systems engineering requires

–People –Process –Tools

MBSE is part of wider Changan Approach to Systems Engineering (CHASE)


Engineers with technical knowledge

People and Infrastructure

19

External expertise for MBSE

Project Management support

Training / Consultancy / Workshops to ensure common understanding

Architects (monitoring process)

Technical Lead

Engineers with SE / MBSE knowledge

Without control project will fail!

Project room + facilities

Successful team requires a range of skills

Team

The Teamwork Balance needed for MBSE!

Don’t overpromote MBSE – It’s just System Engineering using Models.

Leadership Facilitator Mentor


IT infrastru

cture

IT建设

System Architecture & requirements development 系统架构&需求开发

System domain analysis & concept development 系统范围分析&概念开发

MBSE Application at Changan so far!

System Team responsible for ensuring we have a common System Architecture (Interfaces), requirements, System DVP.

Need for effective Information Management, toolset and IT Infrastructure Essential to managing Requirements and Design information.

Configuration Management and Control essential to control requirements and design information.


System modelling using CHASE enables consistent and technically correct implementation confidence in the system design

Historically disciplines working in isolation resulted in fragmented design with low confidence

Auditing of CHASE is led by automated model validation and tailored process training

CHASE unifies the design space making it easier to track overall progress and check consistency

Requirements

System Model

Functions

Interface Spec’s

Test Spec’s

Safety Analysis

Failure Modes

Changan Approach to Systems Engineering (CHASE)


Hardware delivery

Changan Approach to System Engineering (CHASE)

22

CHASE has defined a way to transform the historical approach to develop an integrated holistic design.

Implementation

Test Test Specifications

and Procedures

System Design

Safety Diagnostics

Holistic System Design from single source

CHASE team Delivery teams: Mechanical Design

Software Design Calibration Integration

Test Quality

Manufacturing

Review process All input for

implementation is provided from a single consistent source

Test and validation procedures defined to verify requirements and capture lessons learnt

Software delivery

Test Plans

CHASE


CHASE – Changan Approach to System Engineering

SE Approach

CHASE from basic MBSE and Industry Concepts with Expert help.


bdd [Package] Presentation [Requirements Ontology - High-Lev el]

«block»

Rule

«block»

Context

«block»

Use Case

«block»

System Context

«block»

Need

«block»

Source Element

«block»

Need Description

«block»

Scenario

«block»

Feature

«block»

Goal

«block»

Requirement

«block»

Stakeholder

Context

«block»

Project Context

«block»

Organisational

Context

«block»

Process Context

«block»

Assumption

«block»

Test Specification1..*

validates

1..*

1..*meets

1..*

1

is related to

0..*

0..*

confirms

0..*

1

is related to

0..*

{incomplete}

1..*

validates

1..*

1..*

constrains

1..*

1

is needed to deliver

0..*

1

is related to

0..*

1..*

is elicited from

1..*

0..*

justifies

1..*

1

describes

1

1

is related to

0..*

1..*

describes the context of

1..*

1..*

is needed to deliver 1

5. Process and Methods

24

ACRE approach adapted for Changan context

Concept of Goals, Features and Requirements added

Concept of Assumption added to allow project

to progress in the absence of required

information at the start of the project

Defining the Ontology is critical to ensure common working style and consistent approach – without this the model is just a database


Bringing Everything Together SE/MBSE in the Real World The Creep Example “Vehicle behaviour when utilising an automatic transmission resulting in controlled movement when you let off the brake without accelerator pedal input”

https://www.urbandictionary.com/define.php?term=automatic transmission

https://www.urbandictionary.com/define.php?term=let off

https://www.urbandictionary.com/define.php?term=brake


Problems and Challenges

26

Key Challenge: To develop a highly complex hybrid vehicle in a multinational environment The main problems specifically faced for the Changan team are: The need for effective collaboration The management of engineering complexity How to Introduce and develop the use of MBSE Ensure we Consider modularity and re-use Improve the quality of Changan Products

Key Challenge: Development of a highly complex product in a multi-national environment

With the support of industry expertise, CAUK has made the strategic decision to apply an enhanced System Engineering approach and methods for a new hybrid vehicle project.


Project Background

27

Gen 1 Hybrid Prototype Vehicle

Context • 1st Generation project (2014-2016)

• Low SE/MBSE application • Benchmark and Issues tracked • Lessons learned

• 2nd Generation project (2017 - ) • SE/MBSE focus on key features across the “V” • Development of System and SW Architectures • Integration of key disciplines (System, SW,

HW Functional Safety etc.)

• One Feature “Creep” used to assess MBSE effectiveness and assessment of progress

• Gen2 development applied to Gen 1 Vehicle to

assess effectiveness of MBSE approach Gen 2 Hybrid Prototype Vehicle

Context


Creep Issue Analysis (Gen 1 Project) Root Cause

Analysis

Issue Found

Many Driveability and Performance Issues


Creep Development – Gen 1 (Traditional) vs Gen 2 (MBSE)

Technical Spec issue 1 Technical Spec issue 2

Technical Spec issue 3

Technical Spec issue 1


DR

OM

EM

TM

RD

Why develop a new System/SW Architecture?

GEN 1 Powertrain Control Unit Approach

GEN 2 Powertrain Control Unit Approach


Behavioural Model

Implementation Model


Logical Model



This concept is based on experience and industry examples but implemented quicker.

Model Approach

31

Models allow reuse of the system design in multiple contexts driving effort reduction and consistency in implementation.

Behavioural model focuses on the traditional approach of “features” within an Automotive context

2014 - 2015

Combining Behavioural and Logical Models allows application to multiple implementations

Model Concept

Gen 1 Gen 2.1 Gen 2.2 Gen 2.3


System modelling using CHASE enables consistent and traceable design documentation to support the implementation and validation.

Creep System Engineering Process Output

Behaviour Feature Specification

Feature Test Specification

Feature Test Procedure

Target Book

Implementation Design Specification

Implementation Test Specification

Implementation Test Procedure Implementation (HW and SW)

Feature List

Functional Requirements

Implementation Requirements

Non-Functional Design Specification

Targets

RE-USEABLE

PROJECT SPECIFIC

Model Output


System Design SW Design and Test Vehicle Test

Adapting MBSE Approach for Changan Working Environment

Tailored MBSE Approach

Scenarios


Creep – Different Contexts and Views

34

System Design Specifications provide information to define the required function and Performance.

Scenarios Requirements Views

SSV [UMLDiagram] Calculate Creep Power Demand Connectiv ity [Calculate Creep Power Demand Connectiv ity]

«operation»

Calculate Creep

Power Demand

Physical

«internal message»

Creep Power Demand

«operation»

Calculate

Tractiv e Power

Demand Physical


Driv e Mode


Vehicle Speed


Brake Demand


Power Demand Mode


Driv er Demand

Minimum Power Limit

«operation»

Arbitrate Driv e

Modes Physical

«operation»

CAN 1 Digital

Signal

Conv ersion

«operation»

Calculate Driv er

Demanded

Power Physical


Tractiv e Power

Permission

«operation»

Arbitrate Tractiv e

Phase Physical

«receive»«receive»«receive»«receive» «send»

«send»

«send»

«send»

«receive»

«send»

«send»«send» «receive»«receive»System Contexts & Interfaces

Validation Views

Tractive Phase

Non-Tractive Phase

Standby

Activ e

Initial Shut Down

Inactive [Tractive Power

= Denied]

Active [Tractive

Power = Permitted]States

Tailored MBSE Approach


Creep – Test Vehicle Results (Gen 1 vs Gen 2 on same vehicle)

Old Strategy Gen 1 strategy – Poor Control!!!

New Gen 2 Strategy – Smooth!!!

New Strategy = 78% less energy used for

comparable scenario

Test Vehicle was updated with new software, debugged and running in 1 day Results show that software behaved as expected and showed benefits for system

control and performance


New development approach requires more upfront effort, but overall provides a significant saving in project resource and timing and delivers a more robust solution.

Metric Comparator

Gen 1 – Creep Approach Gen 2 Creep Approach

Up to 78% less energy usage

No of Creep technical requirements 5 75

No of design scenarios/Use Cases 1 36

No of unique test cases 3 36 Number of issues logged

43 6

Time of develop the requirements and initial

design ~20 man days (SW supplier) 45 man days

Time to debug and test

Model In the Loop (MiL)

>5 man days

(Several find and fix issues)

1 man day

Time to integrate into vehicle (Basic Operation) >5 man days 1 man day

Time to debug and validate requirements >> 60 man days

(4 additional SW Releases)

2 man days

(1 additional SW release)

Total: >> 90 days 49 days

Metric Evidence

Creep: Non MBSE vs MBSE Approach (On same Gen 1 vehicle)


MBSE – Considerations, Drawbacks and Issues


Although there are many advantages to adopting MBSE there are several considerations, drawbacks and issues to address: CONTEXT, CONTEXT, CONTEXT

Is MBSE the right approach for you and the application you are considering? Management want to see a Return on Investment.

Building a business case is tricky (seek help and advice) Gaining sponsorship is key!

Don’t over promise and under deliver. Like any new process/methodology it takes time for it to become effective Expect Resistance to Change and manage it! Pick a good example – Typically something that is complex or has been challenging to understand

with existing processes. Use Expertise and Consultants

Try and define what you want first Build a solid foundation - Process, Framework, Ontology etc… Can be costly – focus on improving areas of perceived weakness

Carefully consider the Toolset solution Rubbish in – Rubbish out Can be very expensive investment The more complex the tool the more training you will need Consider Tool interoperability

MBSE – Considerations, Drawbacks and Issues


Summary


Summary

Summary

• Capability Pyramid Development • People, Process, Tools balance

• MBSE tailored and successfully applied • Context, Models, Complexity management • Ontology and Frameworks tailored to you

• Manage MBSE introduction • Build capability gradually • Consultant support, managed business case with

worked example

Thank you – Q&A

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