Hofincons
conducts Maintenance System Effectiveness Audit
to evaluate the status of maintenance function in
an organization and its overall impact on the organization.
The audit will determine the level
of the maintenance management system prevailing
in the organization benchmarked against world-class
maintenance practices.
Methodology
Trained and
experienced consultants of Hofincons will visit
the plant equipped with the audit software, created
based on years of experience in asset management.
The software is designed to bring
out the strengths and weaknesses in the maintenance
management system and brings out areas for improvement.
The present status of maintenance
will be objectively analysed with professional integrity
and quality
Hofincons will perform a gap analysis
to highlight the way things are and the way things
should be.
With poorly organized maintenance
operations, this gap tends to increase continuously.
Benefits
Detailed study
of existing maintenance system and maintenance philosophy
Analysis of the strength and weakness
Comparison with world class maintenance
Remedial measures to overcome the
weaknesses and move towards world class maintenance.
Software:
In-house developed, please contact us for further details.
Sample Report
DETAILED ASSESSMENT REPORT
Plant :
Area :
Assessment Period From: To:
Average Percentage :
A. Management
approach to maintenance(65)
B. Maintenance functional assesment (71)
C. Maintenance planning and scheduling (64)
D. Preventive and predictive maintenance (33)
E. Maintenance performance assessment (0)
F. Computerised maintenance management system
(14)
G. Work order system (0)
H. Stores support to maintenance (79)
I. Operator involvement in maintenance (57)
J. Skill development (70)
K. Lubrication (78)
L. Overall Equipment Effectiveness (OEE) (78)
M. Budget planning and costing (64)
N. Health safety and Environment (92)
O. Supervision effectiveness (100)
P. Engineering support to maintenance (50)
Q. Tools and tackles (80)
R. Maintenance trend (50)
For the preventive maintenance
routines to be efficient, each asset in an operating
plant is to be arranged in hierarchical fashion,
with clearly defined parent–child relationship.
The hierarchy build helps to organize
the maintenance function in an efficient way, giving
an overall perspective of the requirements.
Aided by a well-defined Hierarchy
build, Maintenance planning & scheduling becomes
much more organized, efficient and effective especially
in a computerized maintenance management environment.
Methodology
The basis
for the development of hierarchy is the updated
P & IDs or PEFS, Functional Block Diagrams,
Electrical Single Line Diagrams, Instrument loop
schedule and updated master tag list.
Hierarchy build process starts
with the identification of “Systems”
and their associated “Apex equipment”.
System and Apex equipment are defined as below:
System
Facility representing
a common operating function such as “Fractionation”,
“ Gas Compression”
Apex equipment
Equipment where primary operations
are performed such as “Column”, “Pump”,
“ Tanks/Vessels”.
System or the Apex equipment represents
the highest level in the hierarchy, to which the
sub-level equipment can be attached.
Further sub-level equipment will
be attached based on logical deduction process.
Benefits
The parent–child relationship
of all the equipment of a plant are defined.
This is the basis for the Maintenance
group allocation, which will help in optimized issues
of PM work orders.
Software:
In-house developed, please contact us for further details.
In any plant,
to improve plant availability, the first step is
to identify the critical functions and the equipment
performing those critical functions.
Equipment performing critical functions
will be given more attention during the operation
of the plant to minimize their sudden failure.
Methodology
From the FBDs,
functions performed in the plant will be listed.
A core team of operation, maintenance
will be formed.
Criticality of each of function
and equipment will be analysed based on selected parameters.
Functions and equipment will be ranked as Extreme,
High, Medium and Low.
Equipment performing critical functions
will be selected for equipment criticality analysis.
Benefits
Maintenance requirement of each
asset in the plant will be fixed based on the criticality
rating.
Software:
In-house developed, please contact us for further details.
References
and Standards: NORSOK Standard Z-008: Criticality
Analysis for Maintenance Purposes
With modern
complex plant equipment, the key to improve equipment
availability, product quality and to reduce maintenance
costs is to improve the reliability of plant equipment.
Reliability Centred Maintenance
(RCM) is considered around the world as a proven
methodology to develop world-class asset management
strategies towards this goal.
RCM is defined as a process used
to determine the maintenance requirements of any
physical asset in its operating context
The objectives
of RCM are:
Improve Reliability without
compromising the Technical Integrity
Enhance Availability
Optimize Maintenance Cost
Provide Monitoring Plan to
Sustain Benefit
Methodology
Critical equipment
will be selected for RCM discussion.
A core team of operation and maintenance
personnel will be formed under the guidance of RCM
facilitator.
This team will list all the failure
modes for each type of equipment.
For each failure mode, suitable
preventive or detective task will be identified.
The frequency of performance of
each task will be decided.
While finalized the tasks, condition
monitoring tasks and operator related tasks will
be given preference.
Based on the RCM discussion, maintenance
procedures, crew and frequency will be established.
For certain failure modes, RCM
discussion may lead to redesign or minor modification
in the design of the equipment.
Benefits
Required safety
and environmental protection levels are met or exceeded
Equipment availability is maximized
Cost is minimized (including the
cost of maintenance and repair and the cost of lost
operations due to scheduled and unscheduled down
time).
Asset life is increased
RCM creates a documentation trail
of decisions made in the development of a maintenance
program. This documentation is useful for updating
maintenance requirements as additional operating
experience is gained
Software:
In-house developed, please contact us for further details.
RBI is a method for using risk
as a basis for prioritizing and managing the effort
of an inspection program to rationally allocate
inspection resources
In an operating plant or installation,
a relatively large percentage of risk is associated
with a small percentage of the equipment items
RBI does not aim at extending inspection
intervals, nor does it focus on reducing inspection
cost
Methodology
The RBI method
defines the risk of operating equipment as the combination
of two separate terms:
Consequence of failure
Likelihood of an undetected
failure
The consequence of failure assessment
follows these steps
Definition of scenarios
in which leaks progress to undesirable events
Minor Leak
Small Hole
Large Hole
Rupture
Estimation of the physical
effect of each scenario
Adverse effect on people, equipment,
environment and productivity as a result of the
outcome.
The likelihood of failure assessment
takes into consideration such criteria as
The damage mechanisms
applicable to the item analysed
Internal / External corrosion
Pitting corrosion
Hydrogen embrittlement
Stress Corrosion Cracking
Creep
Fatigue
The inspection history of the
item
The effectiveness of the previous
inspection
Definitions
Risk = Probability
of failure X Consequence of failure
Probability of failure = Likelihood of an event occurring
Consequence of failure = Severity of an outcome of
the event
RBI analysis
RBI analysis is carried
out using any of the following methodologies
Qualitative: Uses engineering
judgments & plant experience as source
Quantitative: Highly
involved calculations using statistical & probability
models
Semi- Quantitative:
Uses the best of both qualitative & quantitative
approach
Risk Assessment
Each item is located on a Risk Matrix
to have a global representation of the risk.
The objective of RBI is to issue
an inspection program to reduce the risk to an acceptable
level.
Definition of mitigation measures
in order to achieve an acceptable risk
Unacceptable
Risk
Acceptable
Risk
RBI IMPLEMENTATION
Issues to
consider when deciding the most appropriate approach
are:
Right level of experience
in units being assessed (especially in the case
of specialized corrosive plant)
What level of influence and
ownership is required for the process
How is RBI to be managed
in the future
Inspection plans to be developed
and inspection results fed back into the process
Quantum of change will be
involved to the way integrity/inspection dept.
works
Benefits
RBI is a formal assessment process
to deliver:
Inspection plans and periods for
equipment based on level of risk
Optimised inspection plans based
on individual damage mechanisms
Operational boundaries, which prevent
unexpected equipment damage mechanisms / rates
Risk mitigation measures and other
actions to safeguard integrity
RBI permits
the shift of inspection and maintenance resources
to provide a higher level of coverage on the high-risk
items and an appropriate effort on lower risk equipment
The technique of Hazard and Operability
Studies, or in more common terms HAZOPS, is used
for 'identifying potential hazards and operability
problems' caused by 'deviations from the design
intent' of both new and existing process plants.
The Hazop Study provides an opportunity
to correct these before such changes become too
expensive, or 'impossible' to accomplish.
HAZOP STUDY METHODOLOGY
Hazop study process involves applying
in a systematic way all relevant keyword combinations
in an effort to uncover potential problems.
The results are recorded in columnar
format under the following headings:
DEVIATION
CAUSE
CONSEQUENCE
SAFEGUARDS
ACTION
Primary Keywords
These reflect both the
process design intent and operational aspects of the
plant being studied.
Flow
Temperature
Pressure
Level
Separate (settle, filter, centrifuge)
Composition
React
Mix
Reduce (grind, crush, etc.)
Absorb
Corrode
Erode
Secondary Keywords
When applied
in conjunction with a Primary Keyword, these suggest
potential deviations or problems.
They are
typically a standard set as listed below:
Word
Meaning
No
The design intent does not occur
(e.g. Flow/No), or the operational aspect is not
achievable (Isolate/No)
Less
A quantitative decrease in the
design intent occurs (e.g. Pressure/Less)
More
A quantitative increase in the
design intent occurs (e.g. Temperature/More)
Reverse
The opposite of the design intent
occurs (e.g. Flow/Reverse)
The Hazop procedure
Hazop is very
much an iterative process, applying in a structured
and systematic way the relevant keyword combinations
in order to identify potential problems.
A team of individuals with expertise
in different areas such as engineering, operations,
maintenance, safety and chemistry should participate
in the discussions.
The team is guided in a structured
brainstorming process, by a leader who provides
structure by using a set of guidewords to examine
deviations from normal process conditions
The guidewords are applied to the
relevant process parameters e.g. flow, temperature,
pressure, and composition in order to identify the
causes and consequences of deviations in these parameters
from their intended values.
Finally,
the identification of unintended (or unacceptable)
consequences results in recommendations for improvement
of the process such as:
Condition Monitoring and Base-Line Vibration Signature
The modern maintenance concept
is to get maximum output from the installed equipment.
This leads to a change from the
time-based maintenance to condition-based maintenance
Condition-based maintenance is
a key technique in the optimization of maintenance
requirement of an equipment.
Available condition monitoring
methods are:
Vibration Monitoring
Lube Oil Monitoring
Temperature Monitoring
Thickness Monitoring
Performance Monitoring
Out of these techniques, Vibration
Monitoring is the single best tool to identify condition
of rotating equipment.
Vibration Monitoring
The biggest advantage is that all
the required data are collected when the equipment
is in operation and without opening it.
Once the exact problems are known,
maintenance activity can be planned to suit the
plant conditions (depending upon the nature of the
problem), necessary spares & crew can be arranged
and minimum downtime is required to bring back the
equipment nearer to new conditions.
Methodology
Hofincons Engineers will visit
the site with portable instruments and collect vibration
data from all the critical equipment, at selected
locations.
After carefully analysing the data
collected, a preliminary report will be given at
site indicating the corrective actions to be carried
out to eliminate the inaccuracies present in the
equipment.
Equipment health condition will
be decided as per ISO 10816 standards.
After eliminating the other inaccuracies,
if unbalance is found to be the reason for high
vibration in the equipment, then using portable
balancing instrument, dynamic balancing will be
done at site.
The detailed
report will contain,
Equipment Sketch
Vibration Data
Equipment Trend Chart
Frequency spectrums
List of equipment in the
Fair and Rough categories
Recommendation for maintenance
for equipment in Fair and Rough
CM Effectiveness report
Benefits
The advantages of condition-based maintenance
over preventive maintenance are:
Unnecessary stopping and opening
of an equipment is avoided.
Probable defects are known prior
to the stoppage.
Equipment outage can be planned
in advance for efficient and effective utilisation
of resources.
Equipment life extension through
trend monitoring.
SIL (Safety Integrity Level) assessments
are used to define the appropriate degree of reliability
when using instrumented systems to control and mitigate
hazards.
rating defines the level of safety performance
of a Instrumentation Safeguarding Loop/system components.
SILs are ranked Levels 1-4, with
a higher level indicating greater safety performance.
Typically, higher SILs are achieved
with more redundancy, more frequent testing, and
diagnostics.
Safety
Integrity Level
Impact
1.
Minor property and production protection.
2.
Major property and production protection. Possible
employee injury.
3.
Employee and community protection.
4.
Catastrophic community impact.
The average probability of failure
to perform its design function on demand (PFD) for
different SIL is given in the following table
Safety
Integrity Level
Required
PFD
1.
2.
3.
4.
Prerequisites for Carrying out
Make sure
that HAZOP study is carried out for the process
Make sure that Target Safety level
is defined for the process. (Target Safety level
is indicated in terms of Frequency of Hazardous
Events per year)
Probability data for the failures
should be available (Sources: Manufacturer, Oreda,
Safety and Reliability handbook)
Methodology for determination of
Establish
the Safety Target Level
Develop accident scenarios for
every initiating event
Establish the probability of occurrence
of initiating event
Establish the reliability of existing
safety system
Determine if the Safety target
level is met, if met, no further evaluation is necessary
Points requiring detailed review
during the actual execution of exercise
Safeguarding Loop /Component performance
Process interfaces
Transmitter and sensor robustness
and quality control
Selection, installation and maintenance
practices
Ambient Temperature Variation
High Static Line Pressures
Drift/Stability
Redundancy
Benefits
Detailed study
of existing safeguarding system
Find out adequacy of the existing
safeguarding system
Well defined Target safety levels
Proposal
of additional measures for improvement of the safeguarding
system for reduced Risk
Software:
In-house developed, please contact us for further details.
References and Standards:
ANSI/ISA S84.01, IEC61511 and IEC61508.
Maintenance System Effectiveness Audit
