ISO/IEC 15026-2:2011 specifies minimum requirements for the structure and contents of an assurance case to improve the consistency and comparability of assurance cases and to facilitate stakeholder communications, engineering decisions, and other uses of assurance cases.
An assurance case includes a top-level claim for a property of a system or product (or set of claims), systematic argumentation regarding this claim, and the evidence and explicit assumptions that underlie this argumentation. Arguing through multiple levels of subordinate claims, this structured argumentation connects the top-level claim to the evidence and assumptions.
Assurance cases are generally developed to support claims in areas such as safety, reliability, maintainability, human factors, operability, and security, although these assurance cases are often called by more specific names, e.g. safety case or reliability and maintainability (R&M) case.
ISO/IEC 15026-2:2011 does not place requirements on the quality of the contents of an assurance case and does not require the use of a particular terminology or graphical representation. Likewise, it places no requirements on the means of physical implementation of the data, including no requirements for redundancy or co-location.