January 16, 2012

Definition File - E-4

Provide a product definition that complies Technical Specification

A. Scope

The Definition File (DD) describes all the functional and physical characteristics of the product.

It guarantees the physical and functional repeatability of the product, and allows, together with the Technical Specification, to identify the configuration of the product resulting from its development. The DD constitutes, with all approved evolutions, a synthesis of all the documentation necessary for its manufacture, inspection, use and maintenance.

The Definition File is based on the RNC document « RNC CNES-E-HB-10-505 Plan type de management des projets et affaires sol »

B. Fundamentals

The Definition File is prepared by the designer of the product, and is initiated no later than phase B ; at this stage, it reflects the solution selected.

During phases C and D, the Definition File receives the detailed description of the product, that is necessary for its manufacture. At this time, it is configuration managed.

C. Typical content

1. Scope

This section defines the scope and coverage of the Definition File.

It provides a brief description of the product and indicates the project phase concerned.

2. Documentation

2.1 Applicable documents

These are all the documents that are required for the definition of the product (STB, DCI, etc.).

2.2 Reference documents

These constitute the bibliography that is necessary in order to prepare the Definition File.

2.3 Glossary

This defines the terminology and acronyms used in the document.

3. Requirements and performance

The functional, performance, interface and environment requirements, and also the operational and implementation requirements, shall be mentioned in this section.


The main performance figures for the spectrometer are:

  • energy level: [20 keV - 8 MeV]
  • resolution: E / = 650 to 1.33 MeV
  • angular resolution: 2°
  • field of view: +/- 8°



4. General description

4.1 Functional breakdown

This section contains the functional breakdown of the product during the various phases of its mission (operating conditions). It shall present the breakdown of the main function into secondary functions that come into play during the main phase of the mission.

4.2 Functional description

This section shall contain a brief presentation of both types of function that are imposed by the Technical Specification:

  • the basic functions, which are broken down into main functions and constraints,
  • the design functions, which depend on the solution concept retained.
  • r each of the functions identified, the values of the functional characteristics shall be stated for:
  • technical performance,
  • Dependability; these values correspond to the requirements of the Technical Specification.






4.3 Layout

This is an overall "photo" which describes the physical layout and location of each of the elements.

It usually comes with a drawing or an artist's illustration.

5. Architecture

This section describes the various architectures selected:

  • mechanical and thermal architecture,
  • optical architecture,
  • electrical architecture,
  • data handling architecture.


This presentation is usually in the form of drawings or diagrams.

The choice of architectures determines the interfaces between the subassemblies.

6. Detailed specification of sub-assemblies

This is a very detailed description of each of the subassemblies, along with the corresponding technical specifications.

The Technical Specification of each subassembly can be written as an independent document listed as an Applicable Document in the Definition File.

In this case, the requirements of the subassembly under consideration shall not be explicitly reiterated in this section, in order to avoid duplicating information that is often anachronic and is a potential source of errors.

7. Description of the product

7.1 Physical characteristics

This section contains, for the product and/or for each component part of the product, the information (in the form of descriptions, drawings or diagrams) concerning:

  • the weight, balance and inertia data of the product and its components. The following shall be stated:
    • whether these values are estimated, calculated or measured,
    • the applicable tolerances,
    • the reference system used,
  • the characteristics of the physical interfaces:
    • between the product and other external products,
    • inside the product, between its main components.


Comment: These interfaces concern the mechanical, electrical, thermal and fluidic interfaces, the characterisations of the overall dimensions, the assembly and accessibility interfaces and the tool interfaces.

7.2 Constraint adaptability characteristics

This section describes how the design :

  • ensures that the product can accept the effect of the stresses applied by the external environment (within the limits specified in the technical specification),
  • restricts, within the limits of the specification, the stress levels generated by the product on its environment.


  • Safety-related characteristics

    This section shall define the characteristics of the devices, facilities and materials that are developed and used to:

    • take safety constraints into account at all stages in the life of the product: manufacture, tests, handling, transport, storage, maintenance, integration and utilisation,
    • prevent or limit unwanted effects (of a mechanical, biological, mechanical, toxic or thermal origin, etc.) on people and property, resulting from an external or internal aggression on the product.
  • Characteristics connected with protection and preservation

    This section shall list the finished-product characteristics of the devices, facilities and materials developed and used to comply with the protection and preservation constraints designed to prevent the deterioration of the product, and the resulting consequences on the availability and reliability characteristics.

  • Maintenance characteristics

    This section gives the list of interchangeable components of the product, the monitoring points, the replacement time line and the sequence of maintenance operations (for the various levels of work).

  • Identification characteristics

    This section states the identification and marking characteristics (codes) of the product (wiring harnesses, sensors, pipes, pyrotechnic components, etc. and the product itself), and also the identification devices (labels, reference and routing marks, etc.).

  • Characteristics connected with packaging and storage

    This section states the conditions and characteristics of the packaging and storage items:

    • standardised container (reference of the standard for pressure, temperature, hygrometry, impacts, etc.),
    • environment and surroundings required for storage, relifing,
    • characteristics of the monitoring and inspection provisions during storage.
  • Characteristics connected with transport and handling

    This section states the characteristics of the devices designed to fit with handling and transport constraints for the product, and associated safety margins. These constraints are based on the product itself (nature, weight, balance, etc.) and on the transport conditions and on the used transport or handling devices.


7.3 Configuration item data list

This section lists the applicable issue of the documentation describing the product.

For each subassembly or component, the parts list shall provide all the information that corresponds to the themes developed below:

  • figures or definition drawings,
  • procured items,
  • assembly operations, adjustments, tests,
  • mandatory manufacturing processes,
  • mandatory inspection processes,
  • delivery conditions,
  • transport and storage,
  • maintenance and operation.


7.3.1 Definition drawings

The following are referenced:

  • an assembly drawing that shows, with the appropriate index numbers, the positions of all subassemblies of the next lowest level that make up the assembly, and also the connecting parts to the next higher assembly,
  • if necessary, and depending on the complexity of the product, the various subassemblies have their own subassembly drawings defined under the same conditions,
  • the list of detailed definition drawings, either directly or by reference to a list that is an integral part of this section.


7.3.2 Procured items

This lists the documents that define the conditions for procuring the subassemblies, equipment, components, parts and materials required to manufacture the product.

This information is provided by referring to:

  • the Definition Files of the subassemblies included,
  • and/or the procurement specifications,
  • and/or the procurement standards which include the applicable acceptance specifications.


For each procured item, mandatory supplier(s) shall be stated.

7.3.3 Assembly operations, adjustments, tests

The documents applicable to the assembly, adjustment and test activities are referenced here. The mandatory tools and facilities that are necessary are also specified, as well as the elements used for their definition, implementation and maintenance in operational condition.

7.3.4 Mandatory manufacturing processes

The documents which define the mandatory manufacturing processes, and if necessary their implementation (qualification of personnel, environment conditions, etc.), their maintenance in operational condition (mandatory inspection and preventive maintenance operations), are referenced here.

Depending on the case, these documents shall consist of process specifications or manufacturing procedures.

7.3.5 Mandatory inspection processes

The documents which define the mandatory inspection processes, and if necessary their implementation (qualification of personnel, environment conditions, etc.), their maintenance in operational condition (mandatory inspection and preventive maintenance operations), are referenced here.

7.3.6 Delivery conditions

The facilities (tools, test benches, software, etc.) delivered with the final product are referenced here, stating which elements are installed and which are delivered as separate items.

7.3.7 Transport, storage, packaging

The documents applicable to the transport, storage and packaging of the end product, during the manufacturing cycle or when the product is made available to the users (specifications, drawings, etc.) are supplied here. These particularly include:

  • general regulations and standards applicable to products for storage, packaging transport and handling,
  • general regulations and standards applicable to product that is dangerous for property or people,
  • constraints and limitations imposed on the product,
  • specific storage, transport, packaging and handling constraints applicable to the product,
  • mandatory facilities and methods for checking that all constraints and limitations are complied with,
  • elements defining the storage, transport, packaging and handling facilities, as well as the conditions for their implementation and for maintaining them in operational condition.


7.3.8 Maintenance and operation

The documents applicable to the maintenance and use of the product are referenced here, from its acceptance to its removal from service.

8. Operating modes

This section shall specify:

  • each operating mode of the product, as described in the Technical Specification, and its detailed characteristics;
  • the state ("on", "off", "standby, etc.) of each subassembly for each operating mode. This data may be recalled in a summary document;
  • the transition between modes, generally in the form of diagrams.


9. External interfaces

The Interface Verification File (DCI) (refer to E-5), if there is one, shall be made applicable here.

If not, refer to the preparation of the Interface Verification File to write this section.

10. Budgets

These are all the performance details and physical characteristics obtained by the product:

  • functional performance,
  • reliability and availability,
  • weight,
  • dimension,
  • dynamic disturbance produced,
  • power,
  • EMC characteristics,
  • alignment,
  • telemetry.


The budgets can be established in separate detail for each subassembly, and presented in the form of a table (Summary Assessments).

11. Requirements concerning the Qualification/Verification of the definition

This section lists the characteristics whose verification must be presented at the end of the ground and flight qualification phases, or during product acceptance.

  • Physical conformity checks on the product

    The physical characteristics mentioned in the "Physical Characteristics" and "Constraint Adaptability Characteristics" paragraphs are the result of analyses, calculations and development tests. These results shall be confirmed during the product qualification tests.

    This section shall list the characteristics for which a verification is mandatory for the qualification of the product. These are characteristics which directly meet the requirements of the Technical Specification, but also those which result from the actual design process.

  • Functional conformity checks on the product

    The functional characteristics mentioned in the "Functional description" and "Functional Breakdown" paragraphs are the result of analyses, calculations and development tests, and also of eventual operational experience. These results shall be confirmed during the product qualification tests.

    This section shall list the functional characteristics for which a verification is mandatory for the qualification of the product (characteristics that meet the requirements of the Technical Specification, but which also result from the actual design process).

    A Qualification/Verification matrix (refer to EF 5) of the requirements and performance figures shall be established.


12. Acceptance requirements

The acceptance specifications shall be referenced, and shall state the mandatory verifications for the acceptance of the product and its components. These specifications define and compile the acceptance operations to be carried out and the criteria to be checked in order to enable the conformity of the product to be judged according to its applicable definition.


RisksNon-obtainment of functional performance
Non-resistance to the environment
 RecommandationsDEFINE THE PRODUCT
Definition File
Status reports
Verification Matrix
Justification File
Assembly, Integration and Test drawing
Integration Procedure
Test Procedure and Report


Activities / documentation

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