ISO/IEC DIS 26580

DRAFT INTERNATIONAL STANDARD
ISO/IEC DIS 26580
ISO/IEC JTC 1/SC 7 Secretariat: BIS
Voting begins on: Voting terminates on:
2020-07-07 2020-09-29
Software and systems engineering — Methods and tools
for the feature-based approach to software and systems
product line engineering
ICS: 35.080
THIS DOCUMENT IS A DRAFT CIRCULATED
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ISO/IEC DIS 26580:2020(E)
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PROVIDE SUPPORTING DOCUMENTATION. ISO/IEC 2020
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ISO/IEC DIS 26580:2020(E)
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Foreword ..........................................................................................................................................................................................................................................v

Introduction ................................................................................................................................................................................................................................vi

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 2

3 Terms and definitions ..................................................................................................................................................................................... 2

4 Overview of feature-based product line engineering .................................................................................................... 4

4.1 Shared Assets ........................................................................................................................................................................................... 5

4.2 Features ......................................................................................................................................................................................................... 6

4.3 Automated means of production ............................................................................................................................................. 7

5 A feature-based specialization of software and systems product line engineering .......................7

line engineering .................................................................................................................................................................................................11

6.1 Key elements of the feature-based PLE factory .......................................................................................................12

6.1.1 Feature catalogue .........................................................................................................................................................13

6.1.2 Bill-of-features and bill-of-features portfolio ......................................................................................13

6.1.3 Shared asset supersets ............................................................................................................................................14

6.1.4 PLE factory configurator ........................................................................................................................................14

6.1.5 Product asset instances .................. .........................................................................................................................14

6.2 Relationships among the key elements of the factory .......................................................................................15

6.2.1 Feature-based abstractions: Feature Catalogue and Bill-of-Features Portfolio .....15

6.2.2 Domain supersets: Feature Catalogue and Shared Asset Supersets ................................16

6.2.3 Assets: Shared asset supersets and product asset instances .................................................17

6.2.4 Product instances: Bill-of-Features Portfolio and Product Asset Instances ..............18

6.3 Reference model layers .................................................................................................................................................................19

6.4 Feature language ................................................................................................................................................................................20

6.5 Support for a hierarchical product line of product lines .................................................................................20

6.6 Other Concerns ....................................................................................................................................................................................21

6.6.1 Configuration management concern ...........................................................................................................21

6.6.2 Traceability concern ..................................................................................................................................................21

6.6.3 Change management concern ...........................................................................................................................22

6.6.4 Access control concern ............................................................................................................................................22

7 Technology layer ................................................................................................................................................................................................22

7.1 Feature language ................................................................................................................................................................................22

7.2 Feature catalogue ...............................................................................................................................................................................25

7.3 Bill-of-features portfolio ..............................................................................................................................................................25

7.4 Shared asset supersets ..................................................................................................................................................................25

7.5 Product asset instances ................................................................................................................................................................26

7.6 PLE factory configurator..............................................................................................................................................................26

7.7 PLE factory development environment ..........................................................................................................................26

8 Technical organization management layer ............................................................................................................................27

26556 ...........................................................................................................................................................................................................27

8.2 Feature catalogue engineering ...............................................................................................................................................28

8.3 Bill-of-features portfolio engineering ..............................................................................................................................30

8.4 Shared asset superset engineering .....................................................................................................................................32

8.5 Automated configuration of the product asset instances ...............................................................................33

8.6 V erification, validation, and product delivery of the product asset instances ..............................34

8.7 Configuration management ......................................................................................................................................................35

8.8 Traceability management ...........................................................................................................................................................37

8.9 Change management ......................................................................................................................................................................38

9 Business organization management layer .............................................................................................................................39

9.1 Incorporation of ISO/IEC 26550, ISO/IEC 26556 and ISO/IEC 26562 processes .....................39

9.2 Fund the PLE factory .......................................................................................................................................................................41

Annex A (informative) Terminology Specialization from ISO/IEC 26550 to ISO/IEC 26580 ..................44

Annex B (informative) UML 2.0 Diagrams for the Feature-based PLE Factory ......................................................47

Bibliography .............................................................................................................................................................................................................................48

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ISO/IEC was prepared by Joint Technical Committee ISO/IEC JTC 1, , Subcommittee SC 7, .

Feature-based Software and Systems Product Line Engineering (“Feature-based PLE” for short) is a

specialization of Software and Systems Product Line (SSPL) engineering and management that is

described in ISO/IEC 26550. That standard describes a very generalized approach to SSPL, focusing on

the benefits of exploiting a common platform of reusable assets for a product family. Each organization

that adopts SSPL under ISO/IEC 26550 is free to do so using their preferred techniques and methods.

What is the motivation for creating a standard for a specialization of SSPL? As the SSPL field has

matured and achieved widespread attention in the industry, a specific and repeatable approach to SSPL

has emerged that takes advantage of commercial off-the-shelf industrial-strength tools and technology,

along with robust best practices for methods and processes, that automate and formalize many of the

processes in domain and application engineering. The result is that less upfront analysis, design, and

implementation effort is required prior to gaining the benefits from the approach.

While SSPL in general provides significant benefits, it also requires a significant investment of time and

effort to adopt and to ultimately achieve those benefits. The Feature-based PLE specialization is a more

narrowly defined solution that can be supported by off-the-shelf tools and methods, which has resulted

in lower investments when an organization adopts SSPL. Feature-based PLE embodies lessons learned

about SSPL practices that have been shown to provide some of the highest benefits and returns (see, for

This document provides a reference model consisting of an abstract representation of the key technical

elements, tools, and methods of Feature-based PLE. The predominant specializations of general SSPL

(1) a mapping from features to asset variation points that is sufficient to drive a fully automated

(2) a methodological shift of all design and implementation effort, change management, and

configuration management to domain engineering, so that application engineering is reduced to

automated configuration of member product instances and testing of configured member products

This document is a specialization of the more general reference model for Software and Systems product

line engineering and management, ISO/IEC 26550. The specialization defined herein addresses a class

of methods and tools referred to as Feature-based Software and Systems Product Line Engineering,

or Feature-based PLE, which has emerged as a proven and repeatable product line engineering and

• define how Feature-based PLE is a specialization within the general ISO/IEC 26550 reference model

• define a reference model for the overall structure and processes of Feature-based PLE and describe

• define interrelationships, and methods for applying the elements and tools of the product line

In this document, products of Feature-based PLE include digital work products that support the

engineering of a system. Some of the artefacts are actually part of the delivered products, while other

• technology providers who wish to provide automated tool support for the reference model and

• champions within an organization who wish to introduce Feature-based PLE throughout that

• IT staff within a PLE organization who will introduce and maintain the necessary technology to

• practitioner stakeholders who will use the provided technology to practice Feature-based PLE;

• technical and business managers who will sponsor and direct the methods necessary to practice

• university professors, researchers, corporate trainers, and other educators who will create and

This document embodies a distinct separation of concerns between the Feature-based PLE technology

providers (the first bullet in the audience list above) and Feature-based technology users (the last four

bullets in the audience list). For each of these stakeholder concerns, the scope of this document is to

define only what is necessary and sufficient to enable Feature-based PLE practice. For technology

providers, this imparts flexibility in how the necessary and sufficient technical capabilities are

provided, as well as the opportunity to offer more expansive capabilities that are possible in an ideal

solution. For technology users, this provides flexibility to select among the technology providers and to

apply the methods that best match their technical and business objectives for Feature-based PLE.

This document, including the product line reference model and the terms and definitions, has been

produced starting from the general approach outlined in reference [10]. In addition to this background

work, lifecycle models from ISO/IEC/IEEE 12207 and ISO/IEC/IEEE 15288 have been used as a baseline.

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements of this document. For dated references, only the edition cited applies. For

undated references, the latest edition of the referenced document (including any amendments) applies.

ISO/IEC/IEEE 12207, Systems and software engineering — Software life cycle processes

ISO/IEC/IEEE 15288, Systems and software engineering — System life cycle processes

ISO/IEC 26550, Software and systems engineering — Reference model for product line engineering and

For the purposes of this document, the terms and definitions given in ISO/IEC/IEEE 12207,

ISO/IEC/IEEE 15288, and the following apply, except where noted. Because Feature-based PLE is a

specialization of the more general product line engineering approach described in ISO/IEC 26550, some

of the terminology used herein is noted as a specialization of the terminology from ISO/IEC 26550, with

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

Note For additional terms and definitions in the field of systems and software engineering, see

ISO/IEC/IEEE 24765, which is published periodically as a “snapshot” of the SEVOCAB (Systems and software

engineering – Vocabulary) database and is publicly accessible at www .computer .org/ sevocab.

specification for a Member Product in the product line, rendered in terms of the specific features from

collection comprising the Bill-of-Features for each Member Product in a product line

characteristic of a Member Product in a product line that distinguishes it from other Member Products

Note 1 to entry: Features can express (a) the customer-visible or end-user-visible variability among the Member

Products in a product line, or (b) distinguishing implementation variability not directly visible to a customer or

end user except through non-functional differences such as price, performance, noise, weight, energy and more.

Note 2 to entry: In Feature-based PLE, features express differences among Member Products. A capability or

other characteristic common to all Member Products in the product line is not modelled as a feature.

model of the collection of all of the feature options and feature constraints available across the entire

formal relationship between two or more features that is necessarily satisfied for all Member Products

syntax and semantics for the formal representation, structural taxonomy, and relationships among the

concepts and constructs in the Feature Catalogue, Bill-of-Features Portfolio, and Shared Asset Superset

technological, organizational, and business infrastructure and processes to support a PLE Factory

Configurator producing Product Asset Instances from Shared Asset Supersets based on a Bill-of-

automated mechanism that produces assets for a specific Member Product by processing the Bill-of-

Features for that Member Product, and exercising the shared assets’ variation points in light of the

toolset for creating, organizing, assembling, and maintaining a collection of elements in a Feature

Catalogue, Bill-of-Features Portfolio, Shared Asset Supersets, and a hierarchy of a product line of

instantiation of a Shared Asset specific to a Member Product, automatically produced by the PLE

Factory Configurator, corresponding to a Bill-of-Features for that Member Product

Note 1 to entry: A Product Asset Instance is analogous to an Application Asset [ISO/IEC 26550] with the proviso

software and systems engineering lifecycle digital artefacts that compose a part of a delivered Member

Product or support the engineering process to create and maintain a Member Product

Note 2 to entry: Typical Shared Assets are requirements, design specifications or models for mechanical, electrical,

and software, source code, build files or scripts, test plans and test cases, user documentation, repair manuals

and installation guides, project budgets, schedules, and work plans, product calibration and configuration files,

mechanical bills of materials, electrical circuit board and wiring harness designs, engineering management

plans, engineering drawings, training plans and training materials, skill set requirements, manufacturing plans

representation of a Shared Asset that includes all content needed by any of the Member Products

Identification of a specific piece of Shared Asset Superset content and a mapping from feature

selection(s) to the form of that content that appears in a Product Asset Instance

Note 1 to entry: In this document, all Features express characteristics that differ among Member Products, which

according to ISO/IEC 26550 would also make every Feature a Variation Point. To avoid this redundancy, 26580

[SOURCE: ISO/IEC 26550, modified to use terms more specific to Feature-based PLE and the PLE

Factory Configurator approach of producing Product Asset Instances from Shared Asset Supersets.]

This section gives a brief informational overview of Feature-based Product Line Engineering, as a

way of introducing key concepts that are important for understanding the purpose and content of this

Software and systems product line engineering emerged some time ago as way to engineer a portfolio

of related products in an efficient manner, taking full advantage of the products’ similarities while

respecting and managing their differences. By “engineer,” we mean all of the activities involved in

planning, producing, delivering, deploying, sustaining, and retiring products. Born in the software

engineering field in the 1970s and 1980s and based largely on the concept of software reuse, PLE has

long been known for delivering significant improvements in development time, cost, and quality of

Early attempts to capture and codify best practices recognized a dichotomy between two sides:

product content that applies to multiple products and product content specific to a single product.

Some referred to the two sides as Domain Engineering and Application Engineering, respectively,

while others referred to Core Asset Development vs. Product Development . Application engineering

was often said to include creating any content that happened to be used only in a single product, and

promoting that content to Domain status only if subsequently used in more. Application engineering

included the obligation to choose and carry out a production strategy – that is, a way to turn the shared

assets into products – that could be different for each type of shared asset, and was often manual and

therefore labour-intensive and error-prone. Whatever they were called, the two sides stood on roughly

However, starting in the early 2000s, the advent of industrial-strength and commercially available

technology designed specifically to support PLE enabled the rapid emergence of a well-defined

specialization of PLE practices. This approach is called Feature-based Software and Systems Product

Under this approach, the technology just mentioned allows Application Engineering, which was so

important under the “classic” PLE approach, to shrink to almost nothing. Products are produced through

the use of high-end industrial-strength automation that configures the shared assets appropriately

for each product. Feature-based PLE explicitly declines to configuration-manage or change-manage

product versions. Instead, the shared assets (and not the individual products or systems) are managed

under CM (Configuration Management). A new version of a product is not derived from a previous

version of the same product, but from the Shared Asset Supersets themselves. Additionally, any defects

are fixed in the shared assets, not the products. The affected products will then be regenerated, into

a form suitable for testing and deployment. Since regeneration has a low and fixed cost, it matters

very little whether 2 or 200 or 2000 products need to be regenerated. Thus, fixing a defect, making a

systematic enhancement, or carrying out any other kind of multi-product change becomes much more

Here are a few more of the key ways that Feature-based PLE differs from its antecedents.

Shared assets are the “soft” artefacts associated with the engineering lifecycle of the products, the

building blocks of the products in the product line. Assets can be whatever artefacts are representable

digitally and either compose a product or support the engineering process to create a product. Examples