This part of IEC 60300 gives guidance on specifying dependability requirements and collating these requirements in a specification, together with a list of the means of assuring the achievement of the dependability requirements.

The guidance provided includes:
- specifying quantitative and qualitative reliability, maintainability, supportability and availability requirements;
- advising acquirers on how to ensure that the requirements can be fulfilled by suppliers;
- advising suppliers to help them meet the acquirer's requirements.

Other obligations, such as legislation and governmental regulations, can also place requirements on items, in addition to any requirements derived in accordance with this document.

Whilst mainly addressing system and equipment level dependability, many of the techniques described in the various dependability related IEC standards can also be applied to products or at the component level. The term "item" is used throughout this document.

This guidance is given in a basic project context where an acquirer obtains an item from a supplier. It can be modified and adapted to other situations as needed.

NOTE 1 This document does not directly consider safety and environment specifications although much of the guidance in this document could also be applied to them.

NOTE 2 This document does not cover items with special multi-stakeholder long-term arrangements (e.g. services provided through Public-Private Partnership procurements) and how dependability is specified in such arrangements.

NOTE 3 The guidance in this document can be applied to some aspects of the specification of requirements relating to software but specific guidance can be found in IEC 62628 [5] and the different parts of the IEC 61508 series [6].