SIST EN 9136:2018

SLOVENSKI STANDARD
SIST EN 9136:2018
01-julij-2018
Aeronavtika - Analiza izvornih vzrokov in reševanje težav (metodologija 9S)
Aerospace series - Root cause analysis and problem solving (9S Methodology)
Luft- und Raumfahrt - Ursachenanalyse und Problemlösung (9S Methodik)
Série aérospatiale - Analyse de cause racine et résolution de problème (9S
méthodologie)
Ta slovenski standard je istoveten z: EN 9136:2018
ICS:
03.120.01 Kakovost na splošno Quality in general
49.020 Letala in vesoljska vozila na Aircraft and space vehicles in
splošno general
SIST EN 9136:2018 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 9136:2018

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SIST EN 9136:2018


EN 9136
EUROPEAN STANDARD

NORME EUROPÉENNE

May 2018
EUROPÄISCHE NORM
ICS 03.120.10; 49.020
English Version

Aerospace series - Root cause analysis and problem
solving (9S Methodology)
Série aérospatiale - Analyse de cause racine et Luft- und Raumfahrt - Ursachenanalyse und
résolution de problème (9S méthodologie) Problemlösung (9S Methodik)
This European Standard was approved by CEN on 20 November 2017.

CEN 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
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 member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

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





EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2018 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 9136:2018 E
worldwide for CEN national Members.

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EN 9136:2018 (E)
Contents Page
European foreword . 3
Rationale . 4
Foreword . 4
Introduction . 5
1 Scope . 6
1.1 General . 6
1.2 Purpose . 6
2 Normative references . 6
3 Terms and definitions . 6
4 General Process . 9
4.1 Basic Principles . 9
4.1.1 Cultural Change . 9
4.1.2 Effective Communication . 10
4.2 When to Apply a Structured Root Cause Analysis and Problem Solving Process . 10
4.3 Process Step Description . 12
5 Process Steps . 14
5.1 Step 0 – Start Immediate Containment Actions . 14
5.2 Step 1 – Build the Team . 16
5.3 Step 2 – Define Problem . 18
5.4 Step 3 – Complete and Optimize Containment Actions . 20
5.5 Step 4 – Identify Root Cause(s) . 21
5.6 Step 5 – Define and Select Permanent Corrective Actions . 23
5.7 Step 6 – Implement Permanent Corrective Action and Check Effectiveness . 24
5.8 Step 7 – Standardize and Transfer the Knowledge Across Business . 26
5.9 Step 8 – Recognize and Close the Team . 27
6 Information and documentation . 29
6.1 Information data definition and documentation. 29
6.2 Forms . 30
6.3 Control of records . 30
(informative) Acronym log . 31
(informative) Information data definition . 32
(informative) Form examples . 48

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European foreword
This document (EN 9136:2018) has been prepared by the Aerospace and Defence Industries
Association of Europe - Standardization (ASD-STAN).
After enquiries and votes carried out in accordance with the rules of this Association, this Standard has
received the approval of the National Associations and the Official Services of the member countries of
ASD, prior to its presentation to CEN.
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 November 2018, and conflicting national standards
shall be withdrawn at the latest by November 2018.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent
rights.
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, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
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Rationale
The objective of root cause analysis and problem solving is to not only reduce the number of issues
(i.e. undesirable conditions, defects, failures), but to minimize their impact on quality, delivery
performance, costs, and ultimately on the customer. Often big issues originate with small problems that
were discovered too late or were discovered, but were never resolved due to a lack of understanding
the actual issue(s), incorrect analysis of the root cause, and/or ineffective actions being taken.
This guidance document was created to provide a methodology for performing root cause analysis to
resolve a significant or recurrent issue [e.g. quality, On-Time Delivery (OTD), process, documentation),
as guidance within the aviation, space, and defence industry and/or when contractually invoked at any
level of the supply chain.
Foreword
In December 1998, the aviation, space, and defence industry established the International Aerospace
Quality Group (IAQG) with the purpose of achieving significant improvements in quality and reductions
in cost throughout the value stream. This organization, with representation from aviation, space, and
defence companies in the Americas, Asia-Pacific, and Europe and sponsored by SAE International,
Society of Japanese Aerospace Companies (SJAC), and AeroSpace and Defence Industries Association of
Europe -Standardization (ASD-STAN), has agreed to take responsibility for the technical content of this
document to promote best practices that would satisfy associated requirements of Aerospace Quality
Management System (AQMS) standards (i.e. 9100, 9110, 9120).
To assure customer satisfaction, aviation, space, and defence industry organizations must produce and
continually improve safe, reliable products that meet or exceed customer and regulatory authority
requirements. This includes having processes in place to detect and eradicate significant and recurrent
issues. This document standardizes methodology to perform root cause analysis and problem solving to
support these efforts. The establishment of a common methodology, for use by organizations at all
levels of the supply-chain should result in improved action plans and a standardized way of exchanging
information between organizations and external stakeholders (e.g. suppliers, partners, customers,
regulatory agencies).
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Introduction
This document has been developed by the IAQG. In accordance with the continual improvement
requirements defined in the 9100-series standards (see Clause 8, “Measurement, Analysis, and
Improvement”), it was deemed useful to promote those industry recognized best practices for
identifying the root causes of nonconformities or undesirable conditions (including potential issues and
conditions) and implementing correction(s) and associated corrective/preventive actions. The process
described in this document was created by comparing and mixing root cause analysis and problem
solving methodologies [e.g. 7 Steps, 8D, Root Cause Corrective Action (RCCA)] used by main actors of
aviation, space, and defence industry.
Unless contractually specified, other root cause analysis processes with slightly different sequencing of
activities and/or different names of process steps may be acceptable, provided that these activities
meet the intent of this document and deliver the same outcomes (i.e. immediate protection, temporary
fix, durable solution, systemic improvement) and provides the same level of information.
Throughout this document, the words “should” and “required” indicate strong recommendations to
apply and correspond to actions that the authors of this document consider important in order to
deliver robust root cause analysis. When strict application of this document is decided by an
organization or is mandated by a customer, they shall be interpreted as an obligation to be complied
with (i.e. interpreted as “shall” and “must”).
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1 Scope
1.1 General
The objective of any organization, as part of continual improvement, is to reduce the number of issues
(i.e. undesirable conditions, defects, failures) and to minimize their impact on quality, delivery
performance, and cost.
This includes having processes in place to detect and eradicate significant and recurrent issues, which
implies having well identified problems, a common understanding of their impact and associated root
causes, and having defined and implemented adequate actions so that these problems, including similar
issues will not happen again.
1.2 Purpose
Propose a methodology to improve the way escapes and issues are managed, including communication
between all parties [e.g. engineering, Materials Review Board (MRB), manufacturing, manufacturing
engineering, supplier, customer] to reduce their impact, contain them as far upstream as possible, and
prevent recurrence (i.e. ensure the right measures are taken at the right location and at the right time).
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN 9100, Quality Management Systems — Requirements for Aviation, Space and Defence Organizations
EN 9110, Quality Management Systems — Requirements for Aviation Maintenance Organizations
EN 9120, Quality Management Systems — Requirements for Aviation, Space and Defence Distributors
EN ISO 9000:2015, Quality management systems — Fundamentals and vocabulary (ISO 9000:2015)
3 Terms and definitions
Definitions for general terms can be found in EN ISO 9000 and the IAQG Dictionary, which is located on
the IAQG website. An acronym log for this document is presented in Annex A.
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
apparent cause
(also referred to as obvious cause, direct cause, or immediate cause)
event or action that immediately results in or precedes the nonconformity
Note 1 to entry: This is generally NOT the root cause.
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3.2
containment
action to control and mitigate the impact of a problem and protect the organization and/or customer
(i.e. stop the problem from getting worse), includes correction, immediate corrective action, immediate
communication, and verification that problem does not further degrade
3.3
contributing causes
causes that by themselves would not cause the problem, but can increase the risk of the issue to occur.
Analysis for these causes generally requires taking a closer look at the existing conditions and
associated actions
3.4
correction
(also referred to as Immediate Correction)
action taken to eliminate a detected nonconformity
[SOURCE: EN ISO 9000:2005, 3.6.6, modified]
Note 1 to entry: A correction can be made in conjunction with a corrective action.
Note 2 to entry: For product nonconformity, correction might be understood as reworking the part, accepting
the nonconformance through concession process, or scrapping the product.
Note 3 to entry: For a system issue, it may include correcting the paper work or issuing a new purchase order.
Note 4 to entry: For a delivery issue, it may include revising to air transportation instead of delivering product
by truck or ship, increasing production rate, etc.
3.5
corrective action
action taken to eliminate the cause of a detected nonconformity or other undesirable situation to
prevent recurrence
[SOURCE: EN ISO 9000:2005, 3.6.5, modified]
Note 1 to entry: A correction can be made in conjunction with a corrective action.
Note 2 to entry: Corrective action may address all types of causes (i.e. apparent, contributing, root causes).
3.6
immediate corrective action
action taken to eliminate, prevent, or reduce the probability of any additional nonconformances related
to the apparent cause from happening again in the short term
Note 1 to entry: These actions may be temporary and should remain in place until the root cause(s) is identified
and permanent RCCA is implemented and verified to be effective.
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3.7
nonconformity
non-fulfilment of a requirement
[SOURCE: EN ISO 9000:2005, 3.6.2]
Note 1 to entry: It may be a nonconforming product, but may also be a late delivery, incorrect paperwork,
incorrect process [production or Quality Management System (QMS) related], etc.
3.8
preventive action
action to eliminate the cause of a potential nonconformity or other undesirable potential situation
[SOURCE: EN ISO 9000:2005, 3.6.4, modified]
Note 1 to entry: Preventive action is taken to prevent occurrence whereas corrective action is taken to prevent
recurrence.
3.9
root cause
original event(s), action(s), and/or condition(s) generating (directly or in cascade) an actual or
potential undesirable condition, situation, nonconformity, or failure
Note 1 to entry: There is sometimes more than one root cause associated to a single nonconformity or one root
cause with multiple contributing causes.
3.10
root cause analysis
process of identifying all the causes (root cause and contributing causes) that have or may have
generated an undesirable condition, situation, nonconformity, or failure
3.11
Root Cause Corrective Action
RCCA
(also referred to as Permanent Corrective Action)
action implemented to address the root cause(s) and contributing cause(s) of the undesirable condition,
situation, nonconformity, or failure; action taken to prevent recurrence
3.12
Root Cause Corrective Action (RCCA) Effectiveness Verification
action taken to verify that the planned corrective action(s) have prevented recurrence of the identified
root cause or contributing causes, and have consequently eradicated the problem
Note 1 to entry: This may include auditing, monitoring of specific metrics, or any other reporting
methodologies.
3.13
Root Cause Corrective Action (RCCA) Implementation Verification
action taken to verify that the planned actions were taken as scheduled
Note 1 to entry: This includes specific actions, milestones, completion dates, and responsibilities.
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4 General Process
4.1 Basic Principles
a) In many instances, organizations and their suppliers do not provide adequate root cause analysis
and problem solving results because:
— no clear criterion exists for an acceptable corrective action plan; organizations are satisfied
when they no longer receive defective parts;
— the organization continues to accept inadequate corrective action plans as priority is given to
schedule versus quality;
— organizations (internal/external) do not have a root cause analysis mind set; people don’t
know or understand the process and/or have not been effectively trained.
b) A robust root cause analysis and problem solving process should provide visibility of the following
information:
— how the issue is managed and communicated between all stakeholders (e.g. engineering, MRB,
suppliers, customer);
— how it is ensured that the actual root cause(s) has been identified;
— how it is ensured that the right measures are taken at the right location, at the right time, and
by the right individuals;
— how containment actions taken to protect the customer and production efforts are identified
and managed.
c) Problem solving approaches can be summarized as:
— Reactive Mode – solving the abnormality that has occurred; gathering and analysing data aims
to provide customer protection and associated countermeasures;
— Proactive Mode – analysing failures and looking for product, process, or system improvements;
— Preventive Mode – putting in place solutions before an undesirable condition, defect, or failure
occurs.
4.1.1 Cultural Change
Cultural change is generally required to progress from a “reactive” mode to “proactive” and/or
“preventive” modes.
a) Examples of traditional behaviours:
— quick fix;
— not taking adequate time for analysis;
— going from one crisis to another;
— looking for the guilty party – “Who did that?”
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— blaming or transferring responsibility;
— generate laundry list of solutions to firefight the symptoms;
— narrow focus taken to address the immediate problem;
— focus on performance metrics/measures (e.g. sales, profits) with hope that processes will
improve by themselves.
b) Expected “systems thinking” behaviour to get “systemic solutions”:
— understanding that many factors contribute to a complex situation;
— fully understanding the actual problem and then addressing the systemic root cause(s);
— permanently fixing and improving performance;
— seeking total understanding of the process – “How did that happen?”
— taking time to understand the big picture; to dialogue and elicit diverse perspectives before
applying the solution;
— focusing on improving processes; actually effecting process performance.
4.1.2 Effective Communication
The behaviour of all process performers and stakeholders are key factors of success in the application
of a robust root cause analysis and problem solving process.
Effective communication is mandatory:
— Within the organization where the problem originated, and between process performers and
stakeholders of the supply chain to ensure effective root cause analysis and corrective action
implementation.
— Between supplier and customer to immediately stop the problem from getting worse, ensure full
understanding of the problem, and verify that implemented solutions are satisfactory.
NOTE The conditions where the customer must be notified should be established and documented. If the
conditions cannot be specified with tangible trigger points, then direction should be given for how to evaluate
each situation to ensure the customer is kept informed, as appropriate.
4.2 When to Apply a Structured Root Cause Analysis and Problem Solving Process
Launching a formal root cause analysis and problem solving process should always be considered, when
an issue (undesirable conditions, defects, and failures) is detected and the cause is unknown or
inconclusive (not obvious). The decision to apply or not apply the process should be made at the
appropriate level of management within the company based on the level of risk and whether the risk
associated is acceptable or not, using a rational decision making process and maintaining records of
significant decisions.
The process should always be applied, if one or more of these conditions exist:
— safety impact (product/personal);
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— product strength, performance, and/or reliability issue;
— high impact on production/maintenance operations:
— stop the production/maintenance line; prevent next operation to occur satisfactorily, etc;
— regulatory authorities and/or customer dissatisfaction;
— costs issue (generated to the customer or the organization);
— disruption of supplier’s process or customer's operations.
— repetitive problems to one part or similar activities/processes;
— difficulty to detect;
— customer request;
— significant quality or QMS issue;
— complex problem that cannot be solved without assistance of other people than those located
where the problem occurred.
Generally speaking, the impact of an issue and the frequency of its occurrence should always be
considered when deciding to launch or not launch a formal root cause analysis (see Figure 1).
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Key
1 Not required
2 Optional
3 Recommended
4 Mandatory
5 Customer request shall always take precedence
X Frequency
Y Impact
Figure 1 — Applying a structured root cause analysis and problem solving process depending on
the impact and frequency of a problem
4.3 Process Step Description
The process is described in nine steps by S0 to S8 (see Figure 2).
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Figure 2 — Root cause analysis general process mapping
The criticality of the problem should be determined, based on evaluation of the risk(s) it generates,
taking into consideration the following elements: the severity of the issue (i.e. its impact on the
business, the product, and/or the customer) its detectability, its probability to occur, etc.
This document defines the elements for each of the nine process steps:
a) objective(s) of the step;
b) output(s) of the step;
c) what are the associated actions for this step;
d) why this step is necessary and the potential risk if no action is taken;
e) when does the activity take place;
f) who are the principle process performers and applicable stakeholders;
g) how to manage this process step so that it is effective, including providing some proposed tools to
be used;
h) communication aspects to take into consideration;
i) specific Items to be considered.
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5 Process Steps
5.1 Step 0 – Start Immediate Containment Actions
a) Objective: To mitigate the impact of the problem, to protect customer operations and the
organization (i.e. stop the problem from getting worse), and verify that the situation does not
deteriorate until the root cause and contributing causes are known.
b) Output: Immediate containment actions defined and implemented; customer protected.
c) What: Actions required to protect the customer and the organization from negative impacts
associated to the problem.
d) Why: If the problem that has been identified is having an impact on the customer or organization,
the situation will continue to deteriorate, especially if no action is taken. This justifies a
development and deployment of a containment plan.
e) When: As soon as the problem is detected and perceived impact on customer or organization
operations is suspected.
NOTE For most critical cases and/or to be in line with customer/regulatory requirements, immediate
containment action may be required within one business working day of detection or less.
f) Who: Should be assigned to an individual or organization, as appropriate.
g) How: Launch immediate preliminary analysis to understand the problem and its immediate impact;
ensuring adequate focus on the effects of the problem, not its cause(s).
Depending on the results of this analysis:
— identify and isolate defective parts or data, and perform immediate containment and/or
correction, as required;
— identify apparent cause and perform immediate corrective action to eliminate, prevent, or
reduce the probability of any additional nonconformances from happening and/or escaping in
the short term.
Typical immediate containment actions may include:
— immediate suspension of Work-in-Progress (WIP);
— stop deliveries;
— recall product (still within the organization or already delivered);
— strengthen associated quality assurance/inspection processes (i.e. inspections, checks, tests);
“Build the wall higher”;
— conduct inventory checks and segregate defective parts;
— temporary update and/or reinforcement of processes, instructions, activities, and documents;
particularly in the case of QMS deficiencies.
Identify immediate/potential risk for affected parts if not detected.
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Determine criticality based on the facts and information available at this time (may evolve at future
steps once there is a better understanding of the problem and associated conditions):
— Can the team assess criticality?
— If not, who should be contacted (e.g. customer, design office, type certificate ho
...