AS/NZS ISO/IEC/IEEE 21839:2021 pdf download – Systems and software engineering — System of systems (SoS) considerations in life cycle stages of a system.
In this document, system of systems considerations are addressed at each of these stages for a system of interest that is intended to interact with other systems (a constituent system of an SoS) as shown in Figure 3. The stages are addressed as follows: Concept (5.1), Development (5.2), Production (5.3), Utilisation and Support (5.4) and Retirement (5.5). As the focus of this document is the life cycle of the constituent system as the system of interest, SoS considerations to be addressed in each stage in the life cycle of a system are presented as a list of questions along with the supporting material. SoS considerations are grouped into three areas: Capability, Technical and Management (including schedule and cost). The document addresses both the benefit to the system of addressing these SoS questions and the risks of failing to address the questions. It identifies the type of information or artifacts that provide the information needed to address the questions and potential actions. In this document, each stage presents three areas to consider: — Capability considerations: In this document, capability refers to the ability to achieve overall user objectives in a mission or business context. User capabilities are often based on the collective effects of multiple physical systems (referred to as “material”) as well as other factors beyond the systems themselves (training, procedures, etc. which are referred to in this document as “non-material”). Typically, the development of an SoI begins with a user need based on an identified gap in capability and a proposed SoI that focuses on filling that capability gap. From the earliest point in its life cycle, understanding the role of the SoI in supporting the needed capability is a key concern, particularly understanding: 1) how the SoI is envisaged to function in the operational or business context, 2) the constraints that context places on the SoI, and 3) the relationships, interfaces and dependencies between the SoI and other systems supporting the capability.
— Management considerations: Consider management issues when dependencies resulting from interactions need to be negotiated with other systems involved (e.g., interfaces, new or changed functionality in other systems). If there is an entity with some type of responsibility that spans an SoS, establish management arrangements with that entity. SoS-related cost and schedule considerations need to be addressed, including identifying costs and schedules associated with external systems. Finally, mechanisms should be in place to monitor the progress in the areas of cross-system dependencies for a prompt identification of any changes or delays which could mean added cost and time. Plans need to be formulated to accommodate these if necessary. Relevant ISO/IEC/IEEE 15288 processes are all the Technical Management processes and all the Agreement processes. In this document, certain considerations need to be addressed at multiple stages, so if a question also applies to more than one stage, this is noted. A system may interact as part of one or more SoS in support of multiple capabilities. In this document, when the interaction of a system with an SoS is discussed, this may include one or more SoS in support of one or more capabilities. Thus, although the terms SoS, capability and context are used in singular form throughout this document, each use can be plural if applicable to the situation. 4.4  SoS technical base Annex A presents what is termed the “SoS technical base”, which reflects the type of SoS level technical information that would ideally be available as a reference to an SoI in addressing wider SoS considerations. As is shown in Figure 1, this document applies to a constituent SoI in an SoS.