3 Applying SMS principles to managing the inspection of Ex electrical equipment
3.6 Audit and review of performance
Organisations should learn from all relevant experience and apply the lessons to move forward and improve the inspection of Ex electrical equipment to assure its continuing integrity. There should be a systematic review of performance based on data from monitoring and from independent audits of the whole Ex SMS. There should be a strong commitment to continuous improvement involving the development of the Ex strategy, systems and techniques of risk control.
Ex electrical equipment integrity performance should be recorded in annual reports.
The key to an effective Ex inspection strategy is good planning being applied to control risks, and resources allocated according to risk priorities. Performance should be measured by setting up suitable monitoring arrangements.
The actual 'as found' integrity of Ex equipment when inspected is the ultimate test of the effectiveness of the Ex inspection strategy (and maintenance strategy). The TPEF, who is responsible for the integrity of the Ex electrical equipment, should ensure that these inspections and associated records are audited and reviewed, that Ex faults are reviewed, and that appropriate trend analysis techniques are applied to identify generic faults. As part of this process an annual and a three-yearly detailed review of the Ex strategy together with the Ex faults identified should be carried out, together with the control measures identified, to vary the level of inspection proportionately with the faults found. Where appropriate, the ICP should be involved in this matter.
The TPEF and ICP should carry out independent Ex inspections to confirm the performance, output measures and verification criteria are appropriate for each grade of inspection, so as to ensure that the Ex inspection strategy is satisfactory and that the Ex electrical equipment is fit for purpose and safe; these independent inspections should be recorded.
Modifications (using computerised maintenance management system (CMMS) data) and repetitive faults (data from previous inspections) for equipment should be taken into account. To enable consistency, where possible, generic fault codes should be used.
Inspection data should be analysed to monitor the effectiveness of the Ex inspection strategy. The information obtained should be shared with other installations in order to promote shared learning and good practice.
Regular reviews of inspection data should be carried out to confirm the integrity of the Ex electrical equipment over its life cycle. These data should be used to support or modify the level of inspection.
All Ex inspections and associated records for initial, visual, close, detailed, continuous supervision, breakdowns, independent audits by the TPEF and ICP, should be audited and reviewed. The Ex inspection strategy should accordingly be revised so as to ensure that all Ex electrical equipment is safe to use in potential hazardous areas.
3.6.1.1 Review meetings
As noted in section 1.3.1, the continuous improvement model set out in HSE Successful health and safety management implies that a significant number of reviews should take place. From a practical standpoint these can often either be combined with other similar activities or several reviews can be combined into one review, provided that in each case the correct people participate and the agenda of such meetings allows sufficient time/focus on the Ex electrical equipment reviews intended to be covered.
A good technique is therefore to identify:
C What reviews should take place and at what frequency.
C Who should attend.
C What information should be available.
From this it should be possible to map these requirements against existing meetings to determine if they can be accommodated within them or if additional stand-alone meetings are required. Decisions as to how reviews should be carried out should be recorded formally: for example, either in the Ex electrical equipment inspection strategy or elsewhere in the organisation’s quality assurance documentation if a suitable location exists. In the latter case, there should be a cross-reference in the Ex electrical equipment inspection strategy to where the information on review implementation is located.
One method of identifying and recording review processes is to adapt the flowchart provided in Annex A of IEC 60079-17 to suit the particular organisation’s structure: this can then show where reviews should take place and how the output of the reviews should feed back into the process.
It should be recognised that reviewing and making improvements based upon feedback is a key process; however, this is often the part of the process which is least well executed. Formally assigning where such reviews should take place is one method of encouraging discipline in execution of the reviews and driving improvements.
3.6.1.2 Output measures
Performance standards for SCEs for offshore installations provide measurable target values for availability/reliability. For other equipment, these can be expressed as KPIs (see 3.6.1.7). These provide a reasonable indication of Ex integrity performance, provided the input data are representative of data over a period in excess of the frequency of inspection.
The TPEF should review current performance against this criterion, together with the KPIs (see 3.6.1.7), and use these to set goals for improvement. This may initiate intervention measures such as a concerted effort to eliminate faults or, conversely, to
review the existing level of inspection where the occurrence of faults has proved to be rare.
To be able to perform this analysis, when any work is completed on Ex electrical equipment the grade of inspection and, where faults are revealed, fault codes should be recorded.
3.6.1.3 Verification of initial Ex inspections
To ensure that the initial inspection of Ex electrical equipment is completed with a suitable audit trail of documentation, a representative inspection should be carried out where required for verification (e.g. for offshore installations subject to OSCR (see section 2.6)), e.g. by taking typically 10% of the total Ex inventory. All inspection results should be recorded and included in the commissioning documentation which should be transferred to the DH’s Ex inspection record system, e.g. a CMMS.
3.6.1.4 Verification of continuing Ex inspections
Where required for verification (e.g. for offshore installations subject to OSCR (see section 2.6)), the TPEF should ensure that an annual independent verification of the Ex electrical equipment inspected and documentation completed is carried out to provide assurance of the quality of work undertaken.
3.6.1.5 Annual review
The TPEF should carry out an annual review of all Ex inspection results. This should be recorded as part of the DH’s demonstration that they are appropriately managing potential ignition risks etc. The results of inspections should be reviewed with Ex electrical inspection personnel to foster ownership and promote a team culture. The desired outcome from this approach is to encourage the recording of all Ex inspections and develop a greater shared understanding of faults found and how to eliminate them.
3.6.1.6 Three-yearly review
The TPEF should carry out a detailed review of the inspection results on a 3-yearly basis.
The review team should consist of those involved in inspection of Ex electrical equipment and should typically include: electrical technicians; contract electrical technicians; the TPEF; the REP; and the ICP. This three-yearly review should confirm that all Ex periodic (i.e. visual and close) inspections and a representative random sample of Ex detailed inspections have been completed in this time period or provide the expert advice for non-compliance (see section 2.9.2).
This team should review the existing Ex inspection strategy and associated inspection data and complete a gap analysis to determine future modifications to the level of inspection and/or change to maintenance procedures to maintain/improve the level of equipment integrity so as to meet the performance standard.
All Ex inspection results and audit and reviews should be recorded as part of the DH’s demonstration that they are appropriately managing potential ignition risks.
3.6.1.7 Key performance indicators
Used correctly, KPIs should be a good method of providing an overview of the health of a system and early warning of a decline in standards: they can be used to trigger action before risk levels rise above what is acceptable. KPIs comprise leading and lagging indicators: the former indicate what will happen in the future; whereas, the latter show what happened in the past. Good practice is to have a balance of both types of KPIs.
It is possible to conceive many other KPIs that could be used; however, KPIs should be used sparingly and there should be a clear identifiable reason for collecting and reviewing the information. It is not uncommon for KPIs to be established to monitor specific areas of under-performance and for such KPIs to be discontinued once there is confidence that good performance exists and has become a normal part of the business
processes. A good test for the need for a KPI is to ask what action will be taken if the value moves adversely from the target value, such as that defined in performance standards.
Where it is determined that an inspection schedule or sample number will not be met, a further risk assessment should be undertaken, or the electrical equipment concerned should be electrically isolated.
If there is more than one group or contractor responsible for different parts of the installation it is useful to have the results arranged per contractor so any difference in performance of the various workgroups can be identified.
Typical examples of KPIs that may be used for performance of Ex equipment, performance of Ex strategy and new installation audits are:
Performance of Ex equipment:
C Failure rate for the period = number of faults found during the period/(period of evaluation (days) x number of Ex electrical equipment inspected for the period).
(This KPI is typically used as part of a performance standard for reliability of SCEs for offshore installations.)
C Total number of action items resulting from an inspection, which can be subdivided by severity into:
− Number of safety items: these are faults where corrective action should be taken in the short term (e.g. <one week).
− Number of integrity items: these are faults where corrective action should be taken in the medium term (e.g. <three months).
− Number of housekeeping items: these are faults that do not affect level of risk but represent a non-compliance with standards (e.g. missing or damaged labelling) where action should be taken in the long term (e.g.
<12 months, such as during the next planned maintenance).
(The safety, integrity and housekeeping items could be further subdivided by fault code (see 3.6.1.8). Comparing the number of each type of action item against the number of equipment inspected and trending the results should enable monitoring of the performance of each type of action item as well as overall performance.)
C Number of action items resulting from an inspection for each lot, which can be subdivided by severity into safety, integrity and housekeeping items (as above) and could be further subdivided by fault code (see 3.6.1.8). (This should enable trending of the performance of various lots.)
Performance of Ex strategy:
% Ex detailed inspections carried out (e.g. in a particular year) =
=
=
=
=
number of Ex detailed inspections carried out x 100 total number of Ex electrical equipment installed
% Ex close inspections carried out (e.g. in a particular year)
% Ex visual inspections carried out (e.g. in a particular year)
% Ex electrical with no recorded Ex inspection (e.g. in a particular year) Inspection backlog
number of Ex close inspections carried out x 100 total number of Ex electrical equipment installed number of Ex visual inspections carried out x 100
total number of Ex electrical equipment installed number of equipment with no recorded Ex inspection x 100
total number of Ex electrical equipment installed number of overdue inspections x 100 total number of Ex electrical equipment installed (This KPI may be part of a broader KPI for all types of SCE.) _
_
_
_
_
New installation audits:
C Total number of faults found during a new installation audit after initial inspection has been completed, which can be subdivided by severity into:
− Number of safety items: faults where corrective action should be taken in the short term (e.g. <one week).
− Number of integrity items: faults where corrective action should be taken in the medium term (e.g. <three months).
− Number of housekeeping items: faults that do not affect level of risk but represent a non-compliance with standards (e.g. missing or damaged labelling) where action should be taken in the long term (e.g. <12 months such as during the next planned maintenance).
3.6.1.8 Fault codes
While KPIs may be useful to gain an overview of performance they are not sufficient to be able to analyse where faults have been found and what type of fault was identified.
Such information is necessary to be able to start identifying the causes of faults, and hence to be able to take appropriate corrective actions.
If only free text is allowed when recording faults it becomes impractical to undertake any form of analysis within a reasonable timescale since there is no means of grouping or classifying the information; therefore fault codes should be used to group or classify faults. Doing so gives an overview of the types of faults, which often is sufficient to identify possible causes. It also should allow the faults to be grouped into smaller, more manageable sets if an in-depth assessment becomes necessary.
Fault codes should be linked to the Ex electrical equipment on which the fault was found: this should allow analysis based upon equipment type rather then type of fault. Ideally, there should also be links to the equipment register such that analysis of fault codes against other factors such as location and age can be carried out. Often this is possible if using a CMMS since such links should already exist to the identification number, tag or whatever system of identification is used.
There follow two examples of the use of fault codes: the former uses the inspection schedules provided in Annex D; whereas the latter is a simpler approach used in a company.
Example
Fault codes are set based upon the items in Table D.1, Table D.2 and Table D.3 for each Ex electrical equipment type of protection concept. For example using Table D.1, code dA7 would mean there has been an unauthorised modification to Ex 'd' electrical equipment; whereas, code nA6 would mean an unsatisfactory enclosure, glass parts and glass-to-metal sealing gaskets and/or compounds for Ex 'n' equipment.
Example
A simpler set of fault codes based upon the type of faults typically encountered are set out in Table 3.4. This includes faults that are likely to be revealed by external inspection (i.e. visual and/or close inspection) as well as faults that are only likely revealed by internal inspection (i.e. detailed inspection).
Table 3.4: Simple set of fault codes based upon the type of faults typically encountered
Fault description Severity Normal
priority Fault code Internal inspections (detailed):
Z Is Zener barrier earth bond <1 ohm Safety 1 Z1
Q Inadequate segregation Is and power Safety 1 Q1
T Ex 'e' loose terminations Safety 1 T1
N Ex 'e' unconnected cores Integrity 2 N2
W Ex 'e' terminations, insulation degradation (water
ingress) Safety 1 W1
F Ex 'd' flame path damaged Safety 1 F1
F Ex 'd' flame path impeded Integrity 2 F2
P Ex 'p' pressurisation control system fault Safety 1 P1 X Ex 'p' certification special requirements X Safety 1 X1 External inspections (visual and close):
B Covers/bolts Safety 1 B1
G Glands/stop ends Integrity 2 G2
E Earthing Integrity 2 E2
U Uncertified equipment used Safety 1 U1
H Certificate inadequate Integrity 3 H3
S Fed-from labels Safety 1 S1
I Ingress Housekeeping 4 I4
D Damage Housekeeping 4 D4
M Mounting Housekeeping 4 M4
C Corrosion Housekeeping 4 C4
R Redundant Housekeeping 5 R5
L Duty/tag numbers Housekeeping 5 L5
In Table 3.4, code B1 would mean a cover damaged or bolts missing with a safety severity and normal priority of 1; whereas, code C4 would mean evidence of corrosion (e.g. paint surface damaged) with a housekeeping severity and normal priority of 4.
Whatever codes are used, the severity of the fault should be indicated by the priority assigned: this can then be used not only in any subsequent analysis but also to ensure any corrective action is taken within an appropriate timeframe (see 3.6.1.7). In Table 3.4, the severity is classified as:
C Safety: priority 1 faults where corrective action should be taken in the short term (e.g. < one week).
C Integrity: priority 2-3 faults where corrective action should be taken in the medium term (e.g. ≤ three months).
C Housekeeping: priority 4-5 faults that do not affect level of risk but represent a non-compliance with standards (e.g. missing or damaged labelling) where action should be taken in the long term (e.g. ≤12 months such as during the next planned maintenance).
The severity assigned here could also be coupled with the probability of a flammable atmosphere being present, as indicated by the pertinent hazardous area classification such that code B1 would be given greater priority where the fault occurred on Ex electrical equipment located in Zone 1 compared to that located in Zone 2.
3.6.2 Auditing
Managing the quality of Ex electrical equipment inspections and records should ensure that the Ex electrical equipment is fit for purpose and safe; data should be of high quality, and supported by trend analysis and auditing.
The auditing process should establish the baseline of Ex electrical equipment integrity, the intended status and provide a clear plan of action on how to make necessary improvements.
Active monitoring of the Ex inspection findings gives an organisation feedback on its performance before an incident occurs and is essential in ensuring that the Ex inspection strategy is fit for purpose.
Organisations should maintain and improve their ability to manage risks by learning from experience through the use of audits and performance reviews. The structured process of collecting independent information (e.g. from electrical TAs and ICPs) on the efficiency, effectiveness and reliability of the Ex inspection strategy and associated inspections and records, and the drawing up of plans for corrective actions should demonstrate management’s commitment to safety.
As part of this auditing process DHs should assure themselves that the safety culture, attitudes, perceptions, competencies and patterns of behaviour of their personnel (including third parties) is appropriate. Organisations with positive safety culture throughout are characterised by open communications founded on trust, by shared perceptions of the importance of safety and by confidence in the efficacy of preventative measures.
3.6.2.1 Audit controls
There should be controls to ensure that audits are applied rigorously and consistently.
An unreliable system may lead to a loss in confidence in its relevance and validity. Typical controls include:
C Ensuring that audits are seen as a positive management tool.
C Securing the competence of auditors.
C Securing the effective implementation of their results and recommendations.
To maximise the benefits, audits should be conducted by competent people independent of the area or activities being audited.
Feeding information on success and failure back into the system is an essential element in motivating personnel to maintain and improve performance. Successful organisations emphasise positive reinforcement and concentrate on encouraging progress on those KPIs that demonstrate improvement in risk control.
Furthermore, subsequent inspections should be adjusted to reflect the results of previous inspections: where the sampling methodology is applied, this should be achieved by modifying the level of inspection.
Inspection data should be analysed to monitor the effectiveness of the Ex inspection strategy. The findings also should be shared with other installations in order to promote shared learning and good practice.