Preface Standards development within the Information Technology sector is harmonized with international standards development. Through the CSA Technical Committee on Information Technology (TCIT), Canadians serve as the Canadian Advisory Committee (CAC) on ISO/IEC Joint Technical Committee 1 on Information Technology (ISO/IEC JTC1) for the Standards Council of Canada (SCC), the ISO member body for Canada and sponsor of the Canadian National Committee of the IEC. Also, as a member of the International Telecommunication Union (ITU), Canada participates in the International Telegraph and Telephone Consultative Committee (ITU-T). At the time of publication, ISO/IEC 15026-2:2011 is available from ISO and IEC in English only. Scope This part of ISO/IEC 15026 specifies minimum requirements for the structure and contents of an assurance case. 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. This part of ISO/IEC 15026 does not place requirements on the quality of the contents of an assurance case. Rather, it places requirements on the existence of the contents and structure of an assurance case. While several notations and slightly varying terminologies are currently used in practice, this part of ISO/IEC 15026 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.