Systems and software engineering - Software life cycle processes

1.1 Overview
This document establishes a common framework for software life cycle processes, with well-defined terminology, that can be referenced by the software industry. It contains processes, activities, and tasks that are applicable during the acquisition, supply, development, operation, maintenance or disposal of software systems, products, and services. These life cycle processes are accomplished through the involvement of stakeholders, with the ultimate goal of achieving customer satisfaction.

This document applies to the acquisition, supply, development, operation, maintenance, and disposal (whether performed internally or externally to an organization) of software systems, products and services, and the software portion of any system, Software includes the software portion of firmware. Those aspects of system definition needed to provide the context for software products and services are included.

This document also provides processes that can be employed for defining, controlling, and improving software life cycle processes within an organization or a project.

The processes, activities, and tasks of this document can also be applied during the acquisition of a system that contains software, either alone or in conjunction with ISO/IEC/IEEE 15288:2015, Systems and software engineering—System life cycle processes.

In the context of this document and ISO/IEC/IEEE 15288, there is a continuum of human-made systems from those that use little or no software to those in which software is the primary interest. It is rare to encounter a complex system without software, and all software systems require physical system components (hardware) to operate, either as part of the software system-of-interest or as an enabling system or infrastructure. Thus, the choice of whether to apply this document for the software life cycle processes, or ISO/IEC/IEEE 15288:2015, Systems and software engineering—System life cycle processes, depends on the system-of-interest. Processes in both documents have the same process purpose and process outcomes, but differ in activities and tasks to perform software engineering or systems engineering, respectively.

1.2 Purpose
The purpose of this document is to provide a defined set of processes to facilitate communication among acquirers, suppliers and other stakeholders in the life cycle of a software system.

This document is written for acquirers, suppliers, developers, integrators, operators, maintainers, managers, quality assurance managers, and users of software systems, products, and services. It can be used by a single organization in a self-imposed mode or in a multi-party situation. Parties can be from the same organization or from different organizations and the situation can range from an informal agreement to a formal contract.

The processes in this document can be used as a basis for establishing business environments, e.g., methods, procedures, techniques, tools and trained personnel. Annex A provides normative direction regarding the tailoring of these software life cycle processes.

1.3 Field of application

This document applies to the full life cycle of software systems, products, and services, including conception, development, production, utilization, support and retirement, and to their acquisition and supply, whether performed internally or externally to an organization. The life cycle processes of this document can be applied concurrently, iteratively and recursively to a software system and incrementally to its elements.

There is a wide variety of software systems in terms of their purpose, domain of application, complexity, size, novelty, adaptability, quantities, locations, life spans and evolution. This document describes the processes that comprise the life cycle of man-made software systems. It therefore applies to one-of-a-kind software systems, software systems for wide commercial or public distribution, and customized, adaptable software systems. It also applies to a complete stand-alone software system and to software systems that are embedded and integrated into larger, more complex and complete systems.

This document provides a process reference model characterized in terms of the process purpose and the process outcomes that result from the successful execution of the activity tasks. Annex B lists examples of artifacts and information items that may be associated with various processes. This document can therefore be used as a reference model to support process assessment as specified in ISO/IEC 33002:2015. Annex C provides information regarding the use of the software life cycle processes as a process reference model. Annex D describes the process constructs for use in the process reference model. Annex I provides the correspondence between this document and ISO/IEC/IEEE 12207:2008 at the level of process name and process outcome.

1.4 Limitations
This document does not prescribe a specific software life cycle model, development methodology, method, modelling approach, or technique. The users of this document are responsible for selecting a life cycle model for the project and mapping the processes, activities, and tasks in this document into that model. The parties are also responsible for selecting and applying appropriate methodologies, methods, models and techniques suitable for the project.

This document does not establish a management system or require the use of any management system standard. However, it is intended to be compatible with the quality management system specified by ISO 9001, the service management system specified by ISO/IEC 20000-1 (IEEE Std 20000-1), and the information security management system specified by ISO/IEC 27000.

This document does not detail information items in terms of name, format, explicit content and recording media. ISO/IEC/IEEE 15289 addresses the content for life cycle process information items (documentation).