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Structural Integrity Management, Ageing and Life Extension John Sharp, Ocean Structures and Cranfield University for PSA seminar on “Structural Integrity Management for Ageing and Life Extension” – April 2010

Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

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Page 1: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

Structural Integrity Management, Ageing and

Life Extension

John Sharp, Ocean Structures and Cranfield University

for PSA seminar on “Structural Integrity Management for Ageing and Life

Extension” – April 2010

Page 2: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

Topics

• Background to Structural Integrity Management (SIM)– Design life, life extension– Assessment process

• Capability maturity modelling• Questionnaire – objectives and content• Selected topics (responses)

– Key performance indicators– Awareness of ageing– Competency– Emergency planning

• Conclusions

Page 3: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

SIM (ISO 19902)

•SIM is a structured method recommended for assessing the condition of a structure•It is a cyclic activity covering data collection, data evaluation, development of an inspection strategy, development and execution of an inspection programme and any consequent remedial works

Page 4: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

From API RP SIM

Initiators include: Life extension, damage to the installation, modifications etc

Page 5: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

Design Life & Life Extension• The design life is the assumed period for

which a structure is to be used for its intended purpose, with anticipated maintenance, but without substantial additional maintenanceand repair from ageing processes being necessary

• Life Extension: This is defined as thecontinued operation of an installation beyond the design life assumed at the time of design or revised following reassessment.

Page 6: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

Life Extension• UKCS: The revised Safety Case Regulations

introduced in 2005 require a revision of the safety case (regulation 14) when there is a “material change” which includes “an extension of the use of an installation beyond its original design life”.

• NCS: Information Duty Regs Requirement on consent to certain petroleum activities: The operator must obtain consent when plans exist for use of a facility exceeding the life span and the assumptions on which approval of the plan for development and operation of petroleum deposits and the plan to install and to operate facilities for transport and utilisation of petroleum is based,

Page 7: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

Assessment Process

• A systematic structural assessment of a facility takes into account any changes in the physical condition that the facility has so far experienced due to ageing or accidental damage.

• It should also be undertaken using current codes and standards; the original design may have been based on earlier versions of these codes and standards.

Page 8: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

Assessment

• Procedures for assessment have only been developed fairly recently– Post hurricane – Gulf of Mexico– Operational phase & life extension

• They are part of : – ISO 19902 section 25 (2007)– NORSOK N-006 (2009)– API RP SIM (2007 draft)

Page 9: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

NORSOK – N-006Assessment of structural integrity for

existingoffshore load-bearing structures

• Sections:– Normative and informative reference– Terms, definitions, abbreviations and symbols– Assessment process– Data collection– Assessment principles for existing structures– Check of fatigue limit states (FLS) including

acceptance criteria– Check of ultimate limit states (ULS) and

accidental limit states (ALS)– Requirements to in-service inspection after

assessment– Documentation of structural assessment

Page 10: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

NORSOK – N-006Life extension

• The assessment for life extension shall conclude on a safe life extension period with respect to technical and operational integrity of the facility.

• The assessment shall further identify the circumstances that will limit the life of the facility without major repairs or modifications, and specify criteria defining safe operation (e.g.permissible cracks lengths, permissible corrosion or remaining thickness, remaining anodes, degrading of paint protection, subsidence, deteriorating compounds (such as H2S, stagnant water), changed load conditions, deteriorated mechanical outfitting),including appropriate factors of safety.

Page 11: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

Assessment of Structural Integrity – ISO 19902

The main elements in the process of initiating and conducting an assessment of a structure are:

a) assemble data on the structure, its history and exposure level;

b) determine if any assessment initiators are triggered,

c) determine acceptance criteria, d) assess the condition of the structure, e) assess the actions, f) screen the structure in comparison with similar

structures, g) perform a resistance assessment, using:

• design level analysis• ultimate strength level analysis• prevention and mitigation,

Page 12: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

Assessment – Acceptance Criteria

• NORSOK N-006 – Fatigue Limit State• Fatigue crack growth

• ISO 19902 - Ultimate limit state• utilizations less than or equal to unity• RSR value of 1.85 or greater

• ISO 19902 – Fatigue• fatigue lives of all members and joints are at least equal

to the total design service life, and the inspection history shows no fatigue cracks or unexplained damage.

• Where fatigue lives of any members and joints are calculated to be less than the total design service life of the structure and fatigue damage has been identified, the structure may be assumed to be fit-for-purpose providing conservative fracture mechanics predictions of fatigue crack growth demonstrate adequate future life and periodic inspection monitors crack growth of the members or joints concerned.

Page 13: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

Capability Maturity Model• A Capability Maturity Model (CMM)

concentrates on three key issues, which are:• the processes the CMM model identifies as

present in managing an activity in a successful organisation;

• the components which influence the quality of that activity;

• how organisational performance scores are established for those components .

Page 14: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

Capability Maturity Model levels – 1 to 3

1. Basic (learner)

Processes absent or ad-hoc with no real understanding.

2. Localised (repeatable)

Processes organised & controlled at local level, no

proper procedures in place.

3. Defined (standardised)

Written procedures available across organisation. An

understanding of basic requirements but little use made

of feedback.

Page 15: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

Capability Maturity Model levels – 4 & 5

4. Managed

Organisation has understanding of setting targets from

experience plus R&D. Processes adapted and

performance improved in response to observed failures.

5. Optimised

Organisation has good understanding of continuous

improvement. Communications and learning optimised

across whole organisation. Training and appropriate

competence are optimised.

Page 16: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

Development of Capability Maturity Models

Previous Offshore Models1. Offshore Design Safety (DCMM) (for HSE)2. Sub-sea Reliability (RCMM) (for BP)3. Offshore Asset Maintenance (C4M) for Energy

Institute

ISO 9004 (2000) also uses five maturity stages for quality management

Page 17: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

Organisation

8.1 Allocation & management of

resources

Repair & mitigate

S2.2Plan and undertake remedial actions

S2.1Determine repair and mitigation measures

Life extensionS3b

Particular issues for ageing of

mobile units – Classed

installations only

S3aManage life extension approval process –production installations

only

Emergency preparedness

S4.1Awareness of potential emergency situations

S4.2Understand significance of potential emergency situations

S4.3Prepare for

potential emergency situations

Assessment

S1.1In-place structural

assessment

S1.2Fatigue

assessment

S1.3Assessment

of robustness

(redundancy, tolerance to

damage)

Documents9.1

Develop DFI resume

9.2In-service

history

Analyses

6.1Evaluate,

analyse and assess

inspection data

Reporting

5.2Manage SIM

data

5.1Reporting on inspections

Supervision11.1QA/QC

11.2Independent verification

Improvements

7.1Evaluate

efficacy of inspection

programme

Resources

Goals & Req.

1.1Develop and update SIM Philosophy

Planning

3.1Inspection planning

Execution

4.1Inspection execution

Maintenance Prog.2.1

Evaluate design,

inspection data and analyses including ageing

2.2Define Long

term inspection

programme

Tech. condition

TechnicalCondition & Report

10.1Assure integrity

10.2Compare with

KPIs

10.3Management

reporting

Inputs Outputs

Page 18: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

Main Processes (1)• Goals & requirements (Develop and update SIM

philosophy)• Maintenance programme (Evaluate design,

inspection data and analyses including ageing; Define long term inspection programme)

• Inspection planning• Inspection execution• Reporting (Manage SIM data; reporting on

inspections)

Page 19: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

Main Processes (2)• Analyses (Evaluate, analyse and assess

inspection data)• Improvements (Evaluate efficacy of inspection

programme)• Organisation( Allocation & management of

resources)• Documents (Develop DFI Resume; In-service

history)• Technical Condition & report (Assure integrity;

compare with KPIs; Management reporting)• Supervision (QA/QC; Independent verification)

Page 20: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

Sub-Processes• Assessment

o In-place structural assessmento Fatigue assessmento Assessment of robustness

• Repair & Mitigationo Determine repair and mitigation measureso Planning and undertaking remedial actions

• Life extensiono Managing the life extension approval process (fixed installations)o Particular issues for ageing mobile units

• Emergency preparednesso Awareness of potential emergency situationso Understanding the significance of [potential emergency situationso Preparation for potential emergency situations

Page 21: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

Objectives of Questionnaire

• Key purpose:– Evaluate operators and rig owners on structural

integrity management– Assess operators’ approaches to life extension

requirements and to emergency preparedness– Document best of current practice– Identify gaps between operators’ practices and

PSA expectations– Identify any improvements required– Approach based on CMM model

Page 22: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

Basis for Questionnaire• 1.1 Goals & Regulations (9)• 2.1 Maintenance programme (5)• 2.2 Definition of long term platform specific inspection programme (4)• 3.1 Inspection planning (5)• 4.1 Execution of inspection• 5.1 Reporting on inspections (3)• 5.2 Management of SIM data (4)• 6.1 (Evaluation, analysis & assessment of inspection data (6)• 7.1 Evaluation of effectiveness of inspection programme (2)• 8.1 Allocation & management of resources (3)• 9.1 Development of DFI resume• 9.2 In-service history (4)• 10.1 Assurance of integrity (4)• 10.2 Compare with KPIs (2)• 10.3 Management reporting (3)• 11.1 QA/QC (4)• 11.2 Independent verification (3)• & sub-processes

Page 23: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

Basis of Questionnaire

• Who undertakes process• How is it managed?• How is it reported• How often updated• Is training given?

Page 24: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

Responses to Questionnaires

• Completed questionnaires received from six duty-holders:

• Letters sent asking for clarification of responses

• Interviews held 16-20th November in Stavanger

• Presentations from each operator plus hard copy

• Report prepared on individual responses to questionnaire and from audits

• Comparison of responses

Page 25: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

Responses to Questionnaires• Maturity levels designated for each main

process• Levels vary from 1 to 4• Most duty-holders had good general

management systems for SIM• Weakest:

– Comparison with KPIs– Independent verification & QA/QC– Understanding ageing (including competency)– Awareness of potential emergency situations

• Strongest:– Allocation & management of resources

Page 26: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

10.2 –compare with KPIs, 11.1 – QA/QC, 11.2 – Verification,

S4.1 –S4.3 Emergency preparedness

Page 27: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

Development of Good Practice

• Developed for key processes from levels 3 and 4 in SI- CMM model

• To be compared with good practice from operators’ responses

• Develop KPIs

Page 28: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

Key Performance Indicators

• KPIs are quantifiable measurements, agreed to beforehand, that reflect the critical success factors (of for example a project.).

• An important requirement is that a KPI must be specific, measurable, achievable, reliable, and time dependant (SMART).

• Can be used to define the state of an offshore structure and changes in KPIs can take account of ageing processes

Page 29: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

Use of KPIs (typical) from Questionnaires

• No. of overdue inspection work orders • Inspection done by competent personnel • No. of repairs vs scheduled repairs • No. of critical inspections overdue more than

90 days • Percentage of planned inspection program

completed• KPI’s are defined and measured as a part of

the barrier verification system where structural integrity is one of the barriers

[most do not relate to state of structure]

Page 30: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

Key Performance Indicators

• Previous work (OMAE 2008) has developed a set of KPIs for structural integrity of offshore structures which relate to aspects which are important for both safety and asset integrity.

• This has been achieved based on a hazard approach, which includes extreme weather, fatigue, corrosion and accidental damage

“Development of Key Performance Indicators for Offshore Structural Integrity”, J.V.Sharp, G.Ersdal, D.Galbraith, OMAE Conference, Portugal, 2008, OMAE2008 57203.

Page 31: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

Key Performance Indicators

• 20 KPIs proposed.– Corrosion (4 )– Fatigue (5)– Extreme weather (2)– Structural capacity/redundancy (2) – Change of use

• 10 relate to original design process• 8 relate to detailed in-service inspection• Some hazards difficult to define suitable KPIs

– Geological/geotechnical hazards– Accidental hazards – Fire and blast

Page 32: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

Development of KPIs –proposed

• Condition survey programme (not updated, not executed, not registered)

• Configuration survey programme (not updated, not executed, not registered)

• ULS, ALS,FLS,SLS, RSR,DSR analyses not updated

• Configuration anomalies not mitigated• Configuration changes not mitigated• Subsidence mitigation plan not established or

not implemented. • Max. subsidence level not established

Page 33: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

Awareness of Ageing –requirement

• Need to be aware of ageing mechanisms• Need to predict future degradation including

wide spread degradation and the consequences from this degradation.

• Requirement to plan inspections and maintenance taking that degradation into account

• Consider potential interaction between ageing mechanisms

• Consider implications of uninspectable areas, their expected state and consequences of failure

Page 34: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

Awareness of Ageing –Responses to Questionnaires• Ageing mechanisms included were:

– Corrosion (all)– Fatigue (all)– Painting/ PFP breakdown– Other mechanisms:

• Foundation settlement• Scour• Subsidence• Marine Growth• Cathodic protection system

• A more rigorous assessment would have been useful, including interaction between mechanisms

Page 35: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

Awareness of Ageing Responses to Questionnaires

• How are ageing effects taken into account in maintenance programme – From previous inspection data and structural

analyses – Periodic surveillance programmes gather data on

ageing effects – Trending of data provides an indication of future

problems– Future scenario’ analyses are performed to ensure

that ageing effects do not compromise integrity.

Page 36: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

Competency• Increasing recognition of importance of

demonstration of competence• Developing regulations, codes & standards

recognising this• Competency in structural integrity

management• ISO 19902, NORSOK N-005, API RP SIM – list

competency requirements in SIM• Part of Questionnaire

Page 37: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

Competency requirement – ISO 19902 (1)

• SIM process (engineer or group of engineers):– Familiar with relevant information involved in the SIM

process– Familiar with relevant information about the specific

platforms under consideration– Knowledgeable in offshore structural engineering– Knowledgeable about underwater corrosion processes

and prevention– Cognisant of the difference between design and

assessment engineering– Experienced in offshore inspection planning– Knowledgeable in inspection tools/techniques– Cognisant of general inspection findings in the offshore

industry

Page 38: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

Competency requirement - ISO 19902 (2)

• Data collection & update –familiar with:– Structural arrangement, inspection techniques, analysis techniques,

interpretation, database admin., material specs. • Inspection Programme – engineer, familiar with the:

– content of the overall inspection strategy, and – with appropriate experience and technical expertise, related to tasks to

be performed

• Offshore Execution of Inspection Programme –supervisors, divers, ROV operators etc qualified to international or equivalent regional standards, with:– knowledge of how and where to look for damage, – experience in NDE methods, – Familiar with structure owner’s data validation & recording

requirements – divers (performing NDE) with accredited training/ qualifications)

Page 39: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

Competency requirement –Feedback from Questionnaire

• Competence requirements– Competency requirements in job descriptions– On-the-job training– Gaps identified - based on these courses, seminars are

suggested – Ageing competency?

• personnel involved in SIM actively seek knowledge about structural ageing effects from the specialist contractors used for life extension assessment

• no formal training given• experience transfer, work experience, technical

literature, conferences• Limited!

Page 40: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

Management of ageing equipment containing fluids or pressure - HSE

report RR509Competencies recommended:• Understanding of relevant regularity requirements,

codes of practice etc• Familiarity with the equipment concerned (design,

construction etc• Understanding of relevant degradation processes• Knowledge to plan inspection and maintenance for

safety• Experience of plant inspection, inspection

techniques & NDT, and their limitations• Understanding of fitness-for-service assessment

Page 41: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

Emergency Preparedness• Awareness: How is emergency preparedness with respect to

structural related integrity managed? • How has the potential for incidents to have an impact on the

structural integrity been identified?• How have potential environmental, external (boat impacts etc) and

damage (cracks and deformations etc) effects on creating emergency situations been identified?

• Understanding: How have the probabilities and consequences of potential emergencies on structural integrity been assessed?

• How has the post-incident integrity for different scenarios been assessed?

• Preparation: How are installation specific features identified and incorporated into the emergency preparedness planning?

• How frequently are emergency exercises for structural hazards undertaken

Page 42: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

Emergency Preparedness -Responses

• Scenarios that can impact structural integrity identified• QRA, risk and Emergency Preparedness Analysis,

design accidental load, ship collision analyses undertaken

• Probability and consequences of identified major accidents are assessed as part of the QRA.

• Structural damages are assessed as consequences to possible accidental events, e.g. collision, fire, explosion

• Emergency Preparedness Strategies and Action Plans are established based on the results of these assessments.

• Contractor has all structural models up and running and can quickly run a reanalysis

Page 43: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

Emergency Preparedness -Responses

• Awareness of potential emergency situations?– Emphasis on ship collision

– Other emergency situations:• Structural degradation e.g. fatigue cracking• Effects of extreme waves, earthquakes etc• Combination of structural damage• Concrete structures - loss of drawdown

• Need for comprehensive risk assessment to identify emergency situations from structural failure

Page 44: Structural Integrity Management, Ageing and Life … Aldring og... · Structural Integrity Management, Ageing and Life Extension ... NORSOK – N-006. Assessment ... Develop DFI resume

Conclusions• SIM an important aspect of managing offshore

installations, including effects of ageing• Concept of design life & processes for life

extension• Assessment process, including ageing and life

extension• Questionnaire – objectives and content• Selected topics for improvement (responses)

– Technical condition evaluation & reporting (KPIs)– Understanding of ageing mechanisms including

competency– Emergency preparedness ( as part of SIM) and

planning– Independent verification & QA/QC