3-5 Item Definition
The Item Definition defines the Item which is going to be built, or for which a subsystem is going to be built. This means that also for suppliers of automotive subsystems the end product in which their subsystems is going to be put to use, i.e. the vehicle, should be defined. This definition includes the description of the item, boundaries, dependencies, environment, etc.
"The first objective is to define and describe the item, its dependencies on, and interaction with, the environment and other items. The second objective is to support an adequate understanding of the item so that the activities in subsequent phases can be performed."
- ISO26262-3 Chapter 5.1
The Item Definition should cover the following topics:
- The functional concept, describing the purpose and functionality, including the operating modes and states of the item
- The operational and environmental constraints
- Legal requirements (especially laws and regulations), national and international standards;
- Behaviour achieved by similar functions, items or elements, if any
- Assumptions on behaviour expected from the item
- Potential consequences of behaviour shortfalls including known failure modes and hazards.
The following boundaries should be made clear in the Item Definition
- The elements of the item NOTE The elements could also be based on other technology
- The assumptions concerning the effects of the item's behaviour on other items or elements, that is the environment of the item
- Interactions of the item with other items or elements
- Functionality required by other items, elements and the environment
- Functionality required from other items, elements and the environment
- The allocation and distribution of functions among the involved systems and elements
- The operating scenarios which impact the functionality of the item
Work Products:
- Item Definition
Item Definition examples:
Click here to download the e-Traction Item Definition
Click here to download the Brace Item Definition
Click here to download the Item Definition Template
