This part of IEC 60706 examines the maintainability requirements and related design and use parameter, and discusses some activities necessary to achieve the required maintainability characteristics and their relationship to planning of maintenance. It describes the general approach in reaching these objectives and shows how maintainability characteristics should be specified in a requirements document or contract. It is not intended to be a complete guide on how to specify or to contract for maintainability. Its purpose is to define the range of considerations when maintainability characteristics are included as requirements for the development or the acquisition of an item. The standard goes on to describe maintainability studies in the preliminary and detailed design phases and their relationships to other maintainability and maintenance support tasks,described in associated standards. Maintainability considerations in design reviews are also included. It is intended that customers acquiring items of equipment will find this standard useful in assisting them to define their maintainability objectives and associated maintainability programmes.