EN 16603-11:2019

Space engineering - Definition of the Technology Readiness Levels (TRLs) and their criteria of assessment (ISO 16290:2013, modified)

This European Standard defines Technology Readiness Levels (TRLs). It is applicable primarily to space system hardware, although the definitions could be used in a wider domain in many cases.
The definition of the TRLs provides the conditions to be met at each level, enabling accurate TRL assessment.

Raumfahrttechnik - Definition des Technologie-Reifegrades (TRL) und der Beurteilungskriterien (ISO 16290:2013, modifiziert)

Dieses Dokument legt Technologie-Reifegrade (TRL) fest. In erster Linie ist es auf die Hardware von Raumfahrtsystemen anwendbar, auch wenn die Festlegungen in einem weiteren Zusammenhang in vielen Fällen Anwendung finden könnten.
Die Festlegung der TRL liefert die für jeden einzelnen Grad zu erfüllenden Bedingungen und ermöglicht so eine genaue Beurteilung des TRL.

Ingénierie spatiale - Définition des Niveaux de Maturité de la Technologie (TRL) et de leurs critères d'évaluation (ISO 16290:2013, modifiée)

Le présent document définit les Niveaux de Maturité Technologique. Il est applicable principalement aux matériels relatifs aux systèmes spatiaux bien que, dans de nombreux cas, les définitions puissent être utilisées dans un domaine plus large.
La définition des TRL fournit les conditions à remplir à chaque niveau, permettant une évaluation de TRL précise

Vesoljska tehnika - Definicija ravni tehnološke zrelosti in merila za ocenjevanje (ISO 16290:2013, spremenjen)

Ta evropski standard določa ravni tehnološke zrelosti (TRL). Uporablja se predvsem za strojno opremo vesoljskih sistemov, čeprav je mogoče definicije uporabiti širše v številnih primerih. Definicija ravni tehnološke zrelosti določa pogoje, ki jih je treba izpolnjevati na posamezni ravni, kar omogoča točno oceno ravni tehnološke zrelosti.

General Information

• Status: Published
• Publication Date: 26-Nov-2019
• Withdrawal Date: 30-May-2020
• ICS: 49.140 - Space systems and operations
• Technical Committee: CEN/CLC/TC 5 - Space
• Drafting Committee: CEN/CLC/TC 5/WG 6 - Upstream standards
• Current Stage: 9060 - Closure of 2 Year Review Enquiry - Review Enquiry
• Start Date: 04-Jun-2025
• Completion Date: 04-Jun-2025
• Mandate: M/496 - Mandate addressed to CEN, CENELEC and ETSI to develop standardisation regarding space industry (Phase 3 of the process)
• Ref Project: SIST EN 16603-11:2020 - Space engineering - Definition of the Technology Readiness Levels (TRLs) and their criteria of assessment (ISO 16290:2013, modified)

Overview

EN 16603-11:2019 - "Space engineering - Definition of the Technology Readiness Levels (TRLs) and their criteria of assessment (ISO 16290:2013, modified)" - is a CEN European Standard that formalizes Technology Readiness Levels (TRLs) for space engineering. The standard defines the conditions and achievements required at each TRL to enable accurate TRL assessment. It is primarily applicable to space system hardware but the TRL framework can be applied across other technical domains.

Key topics and requirements

• Definition of TRLs (1–9): Descriptions and conditions for TRL 1 through TRL 9, covering progression from basic principles observed to flight‑proven systems.
• Criteria of assessment: Conditions and measurable achievements (summarized in a table) that must be met at each TRL to support consistent evaluations.
• Terms and definitions: Standardized glossary for concepts such as element, model, operational environment, critical function/part, laboratory vs. relevant environment, and performance requirements.
• TRL evidence and examples: Illustrative examples and guidance on what constitutes acceptable demonstration (e.g., laboratory proof‑of‑concept, relevant environment testing, flight acceptance).
• Procedural note: The standard specifies the TRL definitions and required achievements but leaves the detailed TRL assessment procedure to the implementing organization.
• Scope limitations: Focuses on space systems and will take precedence over broader-domain EN standards where scope overlaps.

Practical applications

• Technology maturation tracking: Monitor progress of components, subsystems and systems from concept through flight‑proven status.
• Project decision support: Input to programmatic go/no‑go, milestone reviews, and risk/radar assessments.
• Risk reduction and planning: Define verification activities needed to advance TRLs and de‑risk procurement or integration choices.
• Funding and proposal evaluation: Provide objective maturity criteria for research grants, industry bids, and technology demonstration calls.
• Supplier and subcontractor assessment: Establish consistent expectations for delivered hardware maturity.

Who uses this standard

• Space agencies and program offices (for mission readiness and procurement)
• Systems and design engineers, test & verification teams
• Project and program managers evaluating technical maturity
• Contracting authorities and quality auditors
• R&D organizations, universities, and industry developing space hardware

Related standards

• ISO 16290:2013 (originating document)
• ECSS adoption notice ECSS‑E‑AS‑11C (specificities considered in the EN)
• National and international space engineering standards used alongside EN 16603‑11:2019

By adopting EN 16603-11:2019, organizations gain a CEN‑endorsed, space‑specific TRL framework to standardize maturity assessments, improve decision making, and align technical evidence across projects and suppliers.

Standards Content (Sample)

SLOVENSKI STANDARD
01-februar-2020
Vesoljska tehnika - Definicija ravni tehnološke zrelosti in merila za ocenjevanje
(ISO 16290:2013, spremenjen)
Space engineering - Definition of the Technology Readiness Levels (TRLs) and their
criteria of assessment (ISO 16290:2013, modified)
Raumfahrttechnik - Definition des Technologie-Reifegrades (TRL) und der
Beurteilungskriterien (ISO 16290:2013, modifiziert)
Ingénierie spatiale - Définition des Niveaux de Maturité de la Technologie (TRL) et de
leurs critères d'évaluation (ISO 16290:2013, modifiée)
Ta slovenski standard je istoveten z: EN 16603-11:2019
ICS:
49.140 Vesoljski sistemi in operacije Space systems and
operations
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 16603-11
NORME EUROPÉENNE
EUROPÄISCHE NORM
November 2019
ICS 49.140
English version
Space engineering - Definition of the Technology Readiness
Levels (TRLs) and their criteria of assessment (ISO
16290:2013, modified)
Ingénierie spatiale - Définition des Niveaux de Raumfahrttechnik - Definition des Technologie-
Maturité de la Technologie (TRL) et de leurs critères Reifegrades (TRL) und der Beurteilungskriterien (ISO
d'évaluation (ISO 16290:2013, modifiée) 16290:2013, modifiziert)
This European Standard was approved by CEN on 23 August 2019.

CEN and CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for
giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical
references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to
any CEN and CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN and CENELEC member into its own language and notified to the CEN-CENELEC
Management Centre has the same status as the official versions.

CEN and CENELEC members are the national standards bodies and national electrotechnical committees of Austria, Belgium,
Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy,
Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia,
Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom.

CEN-CENELEC Management Centre:
Rue de la Science 23, B-1040 Brussels
© 2019 CEN/CENELEC All rights of exploitation in any form and by any means Ref. No. EN 16603-11:2019 E
reserved worldwide for CEN national Members and for
CENELEC Members.
Contents Page
European Foreword .3
Introduction .4
1 Scope .5
2 Normative references .5
3 Terms, definitions and abbreviated terms .5
3.1 Terms and definitions .5
3.2 Abbreviated terms .9
4 Technology Readiness Levels (TRLs) .9
4.1 General .9
4.2 TRL 1 — Basic principles observed and reported . 10
4.2.1 Description . 10
4.2.2 Examples . 11
4.3 TRL 2 — Technology concept and/or application formulated . 11
4.3.1 Description . 11
4.3.2 Examples . 11
4.4 TRL 3 — Analytical and experimental critical function and/or characteristic
proof-of-concept. 11
4.4.1 Description . 11
4.4.2 Examples . 11
4.5 TRL 4 — Component and/or breadboard functional verification in laboratory
environment . 12
4.5.1 Description . 12
4.5.2 Examples . 12
4.6 TRL 5 — Component and/or breadboard critical function verification in a
relevant environment . 12
4.6.1 Description . 12
4.6.2 Examples . 13
4.7 TRL 6 — Model demonstrating the critical functions of the element in a
relevant environment . 13
4.7.1 Description . 13
4.7.2 Examples . 14
4.8 TRL 7 — Model demonstrating the element performance for the operational
environment . 14
4.8.1 Description . 14
4.8.2 Examples . 15
4.9 TRL 8 — Actual system completed and accepted for flight (“flight qualified”) . 15
4.9.1 Description . 15
4.9.2 Examples . 15
4.10 TRL 9 — Actual system “flight proven” through successful mission operations . 15
4.10.1 Description . 15
4.10.2 Examples . 16
5 Summary table . 16
6 TRL requirements . 18
Bibliography . 19

European Foreword
This document (EN 16603-11:2019) has been prepared by Technical Committee CEN/CLC/TC 5
“Space”, the secretariat of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of
an identical text or by endorsement, at the latest by May 2020, and conflicting national
standards shall be withdrawn at the latest by May 2020.
Attention is drawn to the possibility that some of the elements of this document may be the
subject of patent rights. CEN shall not be held responsible for identifying any or all such patent
rights.
The text of the International Standard ISO 16290:2013 was approved by CEN/CENELEC as a
European Standard with agreed common modifications.
This document originates from ISO 16290:2013 taking into account the specificities of the ECSS
Adoption Notice ECSS-E-AS-11C “Space engineering -Adoption Notice of ISO 16290, Space
systems - Definition of the Technology Readiness Levels (TRLs) and their criteria of assessment”.
These specificities are listed in Clause 5 of this standard.
This document has been developed to cover specifically space systems and will therefore have
precedence over any EN covering the same scope but with a wider domain of applicability (e.g.
aerospace).
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary,
Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland,
Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden,
Switzerland, Turkey and the United Kingdom.
Introduction
Technology Readiness Levels (TRLs) are used to quantify the technology maturity status of an
element intended to be used in a mission. Mature technology corresponds to the highest TRL,
namely TRL 9, or flight proven elements.
The TRL scale can be useful in many areas including, but not limited to the following examples:
a) For early monitoring of basic or specific technology developments serving a given future
mission or a family of future missions;
b) For providing a status on the technical readiness of a future project, as input to the project
implementation decision process;
c) In some cases, for monitoring the technology progress throughout development.
The TRL descriptions are provided in Clause 3 of this document. The achievements that are
requested for enabling the TRL assessment at each level are identified in the summary table in
Clause 4. The detailed procedure for the TRL assessment is to be defined by the relevant
organization or institute in charge of the activity.
The originating document (ISO 16290:2013) of this document was produced by taking due
consideration of previous available documents on the subject, in particular including those from
the National Aeronautics Space Administration (NASA), the US Department of Defence (DoD)
and European space institutions (DLR, CNES and ESA).
1 Scope
This document defines Technology Readiness Levels (TRLs). It is applicable primarily to space
system hardware, although the definitions could be used in a wider domain in many cases.
The definition of the TRLs provides the conditions to be met at each level, enabling accurate TRL
assessment.
2 Normative references
There are no normative references in this document.
3 Terms, definitions and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1.1
acceptance review
activity undertaken to allow the customer to declare acceptance of a product
3.1.2
breadboard
physical model (3.1.12) designed to test functionality and tailored to the demonstration need
3.1.3
commissioning result review
activity undertaken to allow to declare readiness of a product for routine operation and
utilization
NOTE 1 to entry: The commissioning result review is held at the end of the commissioning as part of the
in-orbit stage verification.
3.1.4
critical function of an element
mandatory function which requires specific technology (3.1.22) verification
Note 1 to entry: This situation occurs when either the element or components of the element are new and
cannot be assessed by relying on previous realizations, or when the element is used in a new domain, such
as new environmental conditions or a new specific use not previously demonstrated.
Note 2 to entry: Wherever used in this Standard, “critical function” always refers to “technology critical
function” and should not be confused with “safety critical function”.
Note 3 to entry: Wherever used in this Standard, “critical function” always refers to “critical function of an
element”.
3.1.5
critical part of an element
element (3.1.6) part associated to a critical function
Note 1 to entry: The critical part of an element can represent a subset of the element and the technology
verification for the critical function may be achievable through dedicated tests achieved on the critical
part only.
Note 2 to entry: Wherever used in this Standard, “critical part” always refers to “technology critical part”.
Note 3 to entry: Wherever used in this Standard, “critical part” always refers to “critical part of an
element”.
3.1.6
element
item or object under consideration for the technology readiness assessment
Note 1 to entry: The element can be a component, a piece of equipment, a subsystem or a system.
3.1.7
element function
intended effect of the element (3.1.6)
3.1.8
functional performance requirements
subset of the performance requirements (3.1.16) of an element (3.1.6) specifying the element
functions (3.1.7)
Note 1 to entry: The functional performance requirements do not necessarily include requirements
resulting from the operational environment (3.1.13).
3.1.9
laboratory environment
controlled environment needed for demonstrating the underlying principles and functional
performance
Note 1 to entry: The laboratory environment does not necessarily address the operational environment
(3.1.13).
3.1.10
mature technology
technology defined by a set of reproducible processes (3.1.20) for the design, manufacture, test
and operation of an element (3.1.6) for meeting a set of performance requirements (3.1.16) in
the actual operational environment (3.1.13)
3.1.11
mission operations
sequence of events that are defined for accomplishing the mission
3.1.12
model
physical or abstract representation of relevant aspects of an element (3.1.6) that is put forward
as a basis for calculations, predictions, tests or further assessment
Note 1 to entry: The term “model” can also be used to identify particular instances of the element, e.g.
flight model.
Note 2 to entry: Adapted from ISO 10795, definition 1.141.
3.1.13
operational environment
set of natural and induced conditions that constrain the element (3.1.6) from its design
definition to its operation
EXAMPLE 1 Natural conditions: weather, climate, ocean conditions, terrain, vegetation, dust, light,
radiation, etc.
EXAMPLE 2 Induced conditions: electromagnetic interference, heat, vibration, pollution, contamination,
etc.
3.1.14
operational performance requirements
subset of the performance requirements (3.1.16) of an element (3.1.6) specifying the element
functions (3.1.7) in its operational environment (3.1.13)
Note 1 to entry: The operational performance requirements are expressed through technical
specifications covering all engineering domains. They are validated through successful in orbit operation
and can be verified through a collection of element verifications on the ground which comprehensively
cover the operational case.
Note 2 to entry: The full set of performance requirements of an element consists of the operational
performance requirements and the performance requirements for the use of the element on ground.
3.1.15
performance
aspects of an element (3.1.6) observed or measured from its operation or function
Note 1 to entry: These aspects are generally quantified.
Note 2 to entry: Adapted from ISO 10795, definition 1.155.
3.1.16
performance requirements
set of parameters that are intended to be satisfied by the element (3.1.6)
Note 1 to entry: The complete set of performance requirements inevitably include the environment
conditions in which the element is used and operated and are therefore linked to the mission(s) under
consideration and also to the environment of the system in which it is incorporated.
3.1.17
process
set of interrelated or interacting activities which transform inputs into outputs
Note 1 to entry: Inputs to a process are generally outputs of other processes.
Note 2 to entry: Processes in an organization are generally planned and carried out under controlled
conditions to add value.
Note 3 to entry: A process where the conformity of the resulting product cannot be readily economically
verified is frequently referred to as a “special process”.
[SOURCE: ISO 10795, definition 1.160]
3.1.18
qualification review
activity undertaken to allow the customer to declare qualification of a product
3.1.19
relevant environment
minimum subset of the operational environment (3.1.13) that is required to demonstrate critical
functions of the element (3.1.4) performance in its operational environment (3.1.13)
3.1.20
reproducible process
process (3.1.17) that can be repeated in time
Note 1 to entry: It is fundamental in the definition of “mature technology” and is intimately linked to
realization capability and to verifiability.
Note 2 to entry: An element developed “by chance”, even if meeting the requirements, can obviously not
be declared as relying on a mature technology if there is little possibility of reproducing the element on a
reliable schedule. Conversely, reproducibility implicitly introduces the notion of time in the mature
technology definition. A technology can be declared mature at a given time, and degraded later at a lower
readiness level because of the obsolescence of its components or because the processes involve a specific
organization with unique skills that has closed.
3.1.21
requirement
need or expectation that is stated and to be complied with
Note 1 to entry: Adapted from ISO 10795, definition 1.190.
3.1.22
technology
application of scientific knowledge, tools, techniques, crafts, systems or methods of organization
in order to solve a problem or achieve an objective
3.1.23
validation
confirmation, through objective evidence, that the requirements (3.1.21) for a specific intended
use or application have been fulfilled
Note 1 to entry: The term “validated” is used to designate the corresponding status.
Note 2 to entry: The use conditions for validation can be real or simulated.
Note 3 to entry: May be determined by a combination of test, analysis, demonstration, and inspection.
Note 4 to entry: When the element is validated it is confirmed that it is able to accomplish its intended use
in the intended operational environment (3.1.13).
Note 5 to entry: Adapted from ISO 10795, definition 1.228.
3.1.24
verification
confirmation through the provision of objective evidence that specified requirements (3.1.21)
have been fulfilled
Note 1 to entry: The term “verified” is used to designate the corresponding status.
Note 2 to entry: Confirmation can be comprised of activities such as: performing alternative calculations,
comparing a new design specification with a similar proven design specification, undertaking tests and
demonstrations, and reviewing documents prior to issue.
Note 3 to entry: Verification may be determined by a combination of test, analysis, demonstration, and
inspection.
Note 4 to entry: When an element is verified, it is confirmed that it meets the design specifications.
Note 5 to entry: Adapted from ISO 10795, definition 1.229
3.2 Abbreviated terms
For the purposes of this document, the following abbreviated terms apply.
Abbreviation Meaning
AR acceptance review
CRR commissioning result review
QR qualification review
TRL technology readiness level
4 Technology Readiness Levels (TRLs)
4.1 General
A technology for an element intended for an application reaches the maturity level,
corresponding to TRL 9, when it is well-defined by a set of reproducible processes for the design,
manufacture, test and operation of the element and when, in addition, the element meets a set of
performance requirements in the actual operational environment.
The element under consideration is assumed to be a physical part of a system. Systems are
generally subdivided into sub-systems with potentially several sub-levels. The element can be
any part of the system and is not necessarily a specific sub-system or at a specific sub-level.
A prerequisite for TRL assessment is the identification of the element that is subject to the
assessment. Higher TRLs further require the definition of the performance requirements, and
therefore require the knowledge of the mission and the system where the element is intended to
be used and its operational environment. Performance requirements can be preliminary and
targeting several missions at low TRLs, then progressively refined and verified at higher levels.
The entire TRL scale applies for a given element. Therefore, there is no gradation in the element
complexity when moving from low to high TRLs.
Higher TRLs also imply that the element is in its final form and is being integrated into a system
for validation or use. Therefore, the TRL of a given element may be downgraded if this same
element is used in a different system, unless all environment and interface requirements for the
element in the new system can be demonstrated to be equally or less demanding than for the
original system.
A TRL assessment is valid for a given element and at a given point in time. It may evolve if the
conditions that prevailed at the time of the assessment are no longer valid. Such a situation may
lead to TRL reassessment and degradation, which can occur in particular when the re-build/re-
use of an element is envisioned. Examples are when the obsolescence of the electronics requires
modifications or when the production involves a specific knowledge that has been lost.
The time or effort to move from one TRL to another are technology dependent and are not
linearly connected to the TRL scale. Experience sho
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