ISO/IEC 26551:2012 provides the capabilities of tools and methods that support Software and Systems Product Line (SSPL) requirements engineering. In SSPL requirements engineering, there are three core processes: Product Line scoping, Domain Requirements Engineering, and Application Requirements Engineering.

The major purpose of Product Line Scoping estimates the costs and benefits of a product line, and thereby lets an organization make a go/no-go decision.The costs and benefits estimation results play a pivotal role as an indicator for assessing the effectiveness and efficiency of a product line.

The major purpose of the Domain Requirements Engineering is to analyze commonality and variability for the product line based on the initial features defined in Product Line Scoping, where the major purpose of the Application Requirements Engineering is to define application requirements based on domain requirements assets by reusing, selecting, or newly adding application specific requirements.

For producing multiple products in a product line, the above processes need to be adequately integrated centered around core assets, which is causing the management of domain/application requirements complexities. Thus, the proper supports of methods and tools are essential, and the product line specific capabilities of methods and tools have to be defined.

ISO/IEC 26551:2012 can be used in the following modes:

- By the users: to benefit people who develop, operate, and manage requirements engineering for software and systems product lines.

- By a product line organization: to provide guidance in the evaluation and selection for tools and methods for product line requirements engineering.

- By providers of tools and methods: to provide guidance in implementing or developing tools and methods by providing a comprehensive set of the capabilities of tools and methods for product line requirements engineering.