This document belongs to the documents going along with EN 9200 relating to Project Management Specification. The aims of this document are as follows: ?? to specify emind the concept of (Need) Technical Specification (N)TS; ?? to define the principles and conditions for drawing up@ approving@ using and updating a (N)TS; ?? to propose a template of (N)TS. The template identifies topics and types of related requirements to be covered in a (N)TS without being completely exhaustive or mandatory. It is due to be analysed like a check-list and tailored according to the type of the product of interest@ the context of the bodies involved and the contractual details. The principle of drawing up a (N)TS applies to both tangible and intangible products (e.g. services). The customer/supplier relationship addressed by these principles may also apply within a single organization. The concepts of customer and supplier are discussed in this document without distinction between internal or external relationship. This document implements and adapts EN 16271 to the context@ in order to meet the specific needs of the aeronautical field and more generally the needs of other fields. This document is more explicit about certain aspects of ISO/IEC/IEEE 29148 dedicated to requirements engineering@ such as the responsibility for drawing up a (N)TS on a contractual basis and also the process of drawing it up within a programme (stages and milestones). It also supplements the technical specification framework proposed by ISO/IEC/IEEE 29148@ in particular with requirements relating to safety of operation and result assurance. The relationships existing between Functional Performance Specification (FPS) and (N)TS for expression of needs are given in Annex A.