An industrial experience in introducing Software Product Lines in a software development team devoted to the development of automotive embedded software using a Model-based Design approach.

1. WICSA 2016 – Venice, Italy – April 7th
Introducing Software Product Lines in Model-Based
Design Processes: an Industrial Experience
Domenico Amalfitano
Vincenzo De Simone
Anna Rita Fasolino
Mario Lubrano
Stefano Scala

2. WICSA 2016 – Venice, Italy – April 7th
 Context
◦ Automotive software development process
adopted in FCA Software Factory
 Motivation
◦ Improve efficiency of this software
development process
 Proposed Solution
◦ Introduction of a Software Product Lines
approach for (semi)automatically producing
Product Architectures starting from
specification documents

3. WICSA 2016 – Venice, Italy – April 7th
Variability of the Automotive
Domain
● 222 different vehicle models available in US in
20151
◦ 43 of these were newly introduced models
● Tailoring of vehicles models due to
◦ Customers requirements
◦ Cultural preferences
◦ Different Laws
● Impacts on features provided by cars, such as:
◦ Safety functions
◦ Driving Assistance systems
1 http://ww.statista.com/statistics/200092/total-number-of-car-models-on -the-us-market-since.1990/

4. WICSA 2016 – Venice, Italy – April 7th
Complexity of Automotive
Embedded Software
 More features provided by electronics an
software
◦ Increasing in the number of Electronic Control Units
(ECUs) networked through the body of the car

5. WICSA 2016 – Venice, Italy – April 7th
Complexity of Automotive
Embedded Software - 2
Complexity of automotive embedded software
increases
Excerpt of http://www.informationisbeautiful.net/visualizations/million-lines-of-
code/

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Variability Management Issue
● Variability must be managed to avoid that
the same functions are developed several
times
◦ Case-by-case basis or opportunistic
reuse strategies are adopted
• Error prone
• Not efficient
◦ More systematic reuse approaches
need to be introduced

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Software Product Lines (SPL)
● SPL are a well-know solution for handling
variability and complexity of software
development
◦ “A software product line is a set of software-
intensive systems that share a common,
managed set of features satisfying the specific
needs of a particular market segment or mission
and that are developed from a common set of
core assets in a prescribed way” 1
1 P. Clements and L. Northrop, Software Product Lines: Practices and Patterns.

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Considered Industrial Context
● FCA Software Factory (SWF) devoted to
the development of application software
◦ for Instrument Panel Cluster (IPC) ECUs.
◦ exploiting Model Based Design (MBD)
process

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Adopted Software Development
Process Issues
1. No systematic reuse strategies applied
◦ Exploitation of clone-and-own and copy-paste-
modify approaches when there is the need to
implement same or very similar features for
each new vehicle model
2. Difficulties in propagating modification or
bug-fixing involving common parts of
different software
◦ Need of traceability links between these
software

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Introduction of SPL in the
adopted software development
process

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Proposed solution
● Introduce SPL in the SW Architecture
and Design Phase
◦ For the (semi)automatic generation of
Product architectures (PA):
 tailored for specific vehicle models,
 starting from the specification documents,
 defining a Feature Profile (FP) to specify the
features to provide and the values for
configuring them.
 relying on a SPL infrastructure, named
AutoMative.

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The introduction of SPL in
FCA
● To introduce the SPL we executed two
processes:
◦ Domain Engineering Process
 for developing the SPL infrastructure
◦ Application Engineering Process
 for generating the IPC software products by exploiting the SPL
infrastructure

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Domain Engineering Process
 Identify the IPC features and define its
Product Line Architecture (PLA) that
represent the design that is common
to all SPL products
 Execution of 4 activities:
1. Identify Features
2. Design PLA
3. Define Extraction Rules
4. Develop the SPL infrastructure

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1. Identify Features
 For defining the IPC Feature Model
◦ Identification of the main features of the
IPC and the relationships among them by
manually analyzing specification
documents of multiple vehicle models.
 Specification documents in Excel and Word
format

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2. Design the PLA
 The IPC PLA was designed as a
composition of configurable
MATLAB/Simulink (MS) models
(Additive approach)
◦ For each identified feature, a MS model
was defined in terms of:
 Its composing parametric subsystems and their
Variation Points (VP)s
 The configurable interconnections among these
subsystems
 The rules to instantiate and configure both
subsystems and their interconnections

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2. Design the PLA – the followed
approach
 For defining the configurable
subsystems we:
◦ Analyzed the specification documents
◦ Performed a reverse engineering
process
 to extract reusable models from existing
architectural models

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3. Define the Extraction Rules
 Needed to produce a FP starting from
Excel specification documents of a
given vehicle model.
 They define how to identify Feature
VPs and extract their values and how
to map them in the FP
 They were defined executing reverse
engineering process on different
kinds of specification documents

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3. Define the Extraction Rules –
An example
Excerpt of Specification Documents
Excerpt of Feature Profile

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4. Develop the SPL
Infrastructure
AutoMative● To support the automation of the
Application Engineering process
● The Infrastructure should:
◦ handle the defined PLA, the configurable
subsystems, the extraction and the
transformation rules
◦ produce PA tailored for a specific vehicle
model

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Application Engineering
Process
● It relys on the execution of 2 activities
◦ Definition of the FP
• automatic generation of FP if the specification
documents comply with the models obtained in
the Extraction Rules Phase
• need manual effort on the contrary
◦ Generation of the PA
 generate the MATLAB/Simulink model by
instantiating and configuring the needed
parametric subsystems and their
interconnections

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Application of the Proposed
Approach
Application of the approach for obtaining
the IPC PA tailored for the Fiat Tipo in a
decoupled project
● Initialization of AutoMative Infrastructure by
defining the PLA and by implementing the
parametric subsystems related to the
identified main features
● Definition of the FP according to the
specification documents related to the Fiat
Tipo
● Generation of the PA by instantiating and
configuring of the subsystems according to
the produced FP

22. WICSA 2016 – Venice, Italy – April 7th
Application of the Proposed
Approach - 2
Feature
# Implemented
Parametric
Subsystems
# Identified
Variation
Points
# Instantiated
Parametric
Subsystems
# Filled
Variation
Points
F1 18 93 40 164
F2 17 76 124 418
F3 13 104 208 1664
F4 3 196 3 196
We considered a subset of 4 main features of the IPC

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Application of the Proposed
Approach - Costs
 Domain Engineering Process
◦ Six man-month for developing AutoMative
◦ Eleven man-month for the initialization of the
infrastructure
 Application Engineering
◦ Tens of seconds to generate the FP when no
further manual filling is needed, hours otherwise
◦ Minutes for generating the PAs

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Application of the Proposed
Approach - Discussions
 SPL introduced without impacts on the
entire development process
 The produced PAs can be processed by
the code generation tools
 Improvement in the development of the
architectural models:
◦ current development practices: several
weeks
◦ exploiting AutoMative: hours
 less MATLAB/Simulink design skills required

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Conclusions
 We introduced a SPL approach in the SW
Architecture and Design phase of the
software development process adopted in
FCA SWF
 We developed an SPL infrastructure aimed
at semi-automatically producing IPC PAs
tailored for vehicle models
 We applied the approach and the
infrastructure to develop IPC for the Fiat
Tipo in a decoupled project showing its
feasibility

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Future Work
 Integrate the infrastructure with the other
tools adopted by the company devoted to
the configuration and change management
 Application of the SPL paradigm to the
other software development phases
◦ Requirements
◦ Testing

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Thanks for your attention
Questions?
Further Information:
http://reverse.dieti.unina.it
@REvERSE_UNINA
vincenzo.desimone2@unina.it