Conoco on Path to Reliability Centered Loop Management: Enhancing ROA on the Way Process manufacturers have invested heavily in manufacturing plants and automation systems. A typical manufacturing plant may have hundreds or even thousands of regulatory control loops to enable safe and efficient operations. The most complex units often have advanced process control and optimization schemes implemented on top of these regulatory control loops. All of these systems have a need for tighter process control to enable more effective use of assets that result in higher ROA and ultimately better business performance and profitability. Unfortunately, automation effectiveness deteriorates over time. The lack of a structured methodology for control loop maintenance is a contributing factor that erodes performance. A manufacturing plant typically has only two or three control engineers who each have responsibility for a large of number of loops, yet they often have no means of identifying where to focus their efforts so that their work has the largest economic impact on plant performance.

1. THOUGHT LEADERS FOR MANUFACTURING & SUPPLY CHAIN
ARC INSIGHTS
By Tom Fiske
Most manufacturers are not extracting all
the value possible from their assets. Even
small incremental improvements can fall
straight to the bottom line. The lack of a
structured methodology for control loop
maintenance is eroding ROA. Conoco has
adopted a Six Sigma approach that helps its
overburdened staff locate and fix the most
economically beneficial problems while
avoiding unnecessary and costly repairs.
INSIGHT# 2003-11MP
FEBURARY 20, 2003
Conoco on Path to Reliability Centered Loop
Management: Enhancing ROA on the Way
Keywords
Asset Management, Control Loop Monitoring, Operational Excellence
(OpX), Return on Asset (ROA), Reliability Centered Maintenance (RCM)
Summary
Process manufacturers have invested heavily in manufacturing plants and
automation systems. A typical manufacturing plant may have hundreds or
even thousands of regulatory control loops to enable safe and efficient op-
erations. The most complex units often have advanced process control and
optimization schemes implemented on top of these regulatory control
loops. All of these systems have a need for
tighter process control to enable more effective
use of assets that result in higher ROA and ul-
timately better business performance and
profitability.
Unfortunately, automation effectiveness dete-
riorates over time. The lack of a structured
methodology for control loop maintenance is a
contributing factor that erodes performance. A
manufacturing plant typically has only two or three control engineers who
each have responsibility for a large of number of loops, yet they often have
no means of identifying where to focus their efforts so that their work has
the largest economic impact on plant performance.
Conoco has adopted a Six Sigma Operational Excellence (OpX) approach to
loop assessment and maintenance. They are using Loop Scout from Hon-
eywell to continuously measure, analyze, improve, and control their loop
performance. At their initial pilot refining site, they have reduced energy
costs by identifying an oscillation of six interacting loops in the fuel gas sys-
tem of heaters that feed two crude units. Repairing the malfunctioning
pressure valve resulted in a savings of $500k per year. They are currently
adopting a Reliability-Centered Maintenance (RCM) strategy that helps de-
termine the appropriate maintenance response based upon the consequence
of failures. Conoco’s saving in turnaround avoidance greatly exceeds its
energy savings.

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©2003 • ARC • 3 Allied Drive • Dedham, MA 02026 USA • 781-471-1000 • ARCweb.com
Analysis
One of the defining characteristics of the process industries is the utilization
of asset intensive manufacturing operations and consumes large quantities
of raw materials and energy to produce products. ROA is often used as a
key measure of operational performance because it indicates how well a
company uses its assets to generate income. The manufacturer’s most criti-
cal challenge lies in improving ROA by managing its assets, material, and
energy usage in the most effective way possible.
Control Loop Maintenance Is Crucial to Increasing ROA
The economic benefits that automation and control systems have bestowed
on manufacturing operations are undeniable. However, automation sys-
tems operations require effective regulatory control. Unfortunately, this is
not always this case due to poor loop tuning, equipment problems, or im-
proper control strategies. For example, Honeywell has analyzed over 250
thousand control loops and found that only one-third have acceptable vari-
ability transfer performance. Even if a process were running at optimal
economic conditions, performance deterioration occurs from changes in
production objectives, wearing of equipment, etc.
Organizations must be constantly vigilant to prevent control loop variabil-
ity transfer performance deterioration since they are essential to operating
the plant effectively. However, control loop performance monitoring and
maintenance is a balancing act; doing too much can waste time and money
while doing too little can cause poor variability transfer performance and
unscheduled downtime. Since control engineers are typically responsible
for hundreds of control loops, it is not possible or even advisable to attempt
to have all your loops run optimally since the time, effort, and expense are
prohibitive. Users need tools to help them achieve a good balance by point-
ing out which control loops under the current situation provide the largest
benefit when running optimally.
RPM Systems –Provide Information When it Is Needed
While automation has fostered significant operational improvements, the
best results occur when highly skilled workers augment automation and
control systems with their knowledge, skills, and experience to manage
plant performance. At the ARC Driving Operational Excellence in Manu-
facturing Forum held this month, the overwhelming consensus of
presenters was that providing pertinent and timely information to opera-
tional personnel is a critical success factor in improving performance.

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©2003 • ARC • 3 Allied Drive • Dedham, MA 02026 USA • 781-471-1000 • ARCweb.com
One of the key elements needed to aid process manufacturers in their quest
to increase profitability is a Real-time Performance Management (RPM) sys-
tem. RPM systems leverage the wealth of information contained and
generated by process automations systems while supporting continuous
improvements and OpX tenets. For an RPM system to reach its true poten-
tial, current performance information must be made available in a time
frame that is consistent with the job employees do. It is imperative to de-
liver the right information to the right person at the right time and in the
right context so that he can take the right actions within the production cy-
cle to improve plant performance. The information must be incorporated
into the workflow process so that actionable items are easily derived and
generated from the associated analysis.
Loop Scout Delivers at Conoco
About two years ago, Conoco (now ConocoPhillips) began using Loop
Scout, a loop monitoring and reliability centered maintenance solution from
Honeywell. The initial pilot application was at its Denver refinery. The
facility is a small refinery with a capacity of 58,000 BPD and produces a
slate of petroleum products marketed in Colorado. Conoco recognizes the
benefits of having a strong asset management program. Conoco believes
they can increase operational performance and decrease maintenance cost
by applying asset management techniques to control loops.
Consequently, a joint Six Sigma project was initiated between Conoco and
Honeywell to optimize control loop maintenance. The initial objective was
to have all their control loops run optimally. After further contemplation,
however, they decided that was just not feasible. Instead, a more reason-
able objective was declared: to optimally deploy maintenance resources.
The facility has 642 control loops and a small staff that shared ownership
among engineering, operations, and maintenance. Buy-in for the project
was obtained from all three groups so that workflow processes could be
coordinated since the results impacted everyone. A Six Sigma DMAIC (De-
fine, Measure, Analyze, Improve, and Control) work process for their
control loop assessment and maintenance was developed over six weeks.
As part of the Define and Measure step, Loop Scout was used to collect per-
formance data on all 642 control loops. Loop Scout computes
approximately 10 performance metrics to help identify the greatest business
performance improvement opportunities by finding where major problem
areas exist. The performance of each loop is categorized as excellent, ac-
ceptable, open loop, fair, or poor. Applying their process knowledge,

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©2003 • ARC • 3 Allied Drive • Dedham, MA 02026 USA • 781-471-1000 • ARCweb.com
Conoco assigned each loop to a criticality level that reflects its importance
in terms of the economic impact it has on the plant. Of the 642 control
loops, it was determined that 153 had high economic impact on the plant.
During the analysis step, all loops are prioritized based upon a combination
of its performance and criticality to generate a narrowly focused opportu-
nity list of economically significant, poor performing subset of control
loops. The importance of this step cannot
be over emphasized, since finding the right
loops that have a high impact on business
performance is difficult. Loop Scout pro-
vides another set of metrics and performs
detailed diagnostics to determine the root
cause of the problem so corrective actions
can be taken. This is often difficult, as a
problem can have several causes each con-
tributing to poor performance.
Loop Scout’s reports are generated as
needed from continuous plant data in time
for employees to perform their functions.
Since it is a service, it does not overload
Conoco’s staff. The reports put the metrics
in the proper context to show why a loop is at the top of the list, how it has
changed over time, and how its performance is related to other assets. Al-
most immediately, a 33 minute oscillation of six control loops in the fuel gas
system (highly critical with fair performance) of the two four-pass heaters
that feed two crude towers was identified. Loop Scout diagnostic metrics
indicated that a pressure valve stiction problem was the most likely culprit.
A work order package was issued to fix the problem as part of the DMAIC
improve step. The unit was taken offline, the pressure valve repaired, and
the loops retuned. Validation of the improvements was also done using
Loop Scout. The resulting cost savings in the reduction of fuel gas was
close to $500k/year. Throughout the following year, numerous opportuni-
ties arose, such as the identification and repairing of 12 sticky valves, which
contributed to APC downtime and decreased yields on the FCC unit. With
the success of the pilot project behind them, Conoco is rolling out Loop
Scout to three other refineries.
Today, Conoco continues to periodically scan and monitor loops with Loop
Scout to ensure they perform effectively. In addition, Conoco’s greatest
Repair / Replace
Measurement Device
Repair / Replace
Measurement Device
TuneControllerTuneController
Investigate
andRepair Valve
Investigate
andRepair Valve
Reactive
Maintenance
WorkOrders
fromOps
Reactive
Maintenance
Work Orders
fromOps
Developand
Execute
Work
Packages
Develop and
Execute
Work
Packages
Sort and
Prioritizebased
on Performance
andCriticality
Sort and
Prioritizebased
onPerformance
andCriticality
AssessRepair
Effectiveness
AssessRepair
Effectiveness
Assess
Performance,
Stiction, Common
Oscillations,
Tuning Changes
Assess
Performance,
Stiction, Common
Oscillations,
Tuning Changes
AssessCriticalityUsing
RankingMethod
AssessCriticalityUsing
RankingMethod
Implement
Criticality-
based
Schedule
Implement
Criticality-
based
Schedule
Collect Time
SeriesData
LegendLegend
RecurringHuman
Activity
RecurringHuman
Activity
Automatic
Activity
Automatic
Activity
One-timeHuman
Activity
One-timeHuman
Activity
TrackBenefits
usingSix
SigmaMethods
TrackBenefits
using Six
Sigma Methods
Set Benefits
Targetsand
Expectations
Set Benefits
Targetsand
Expectations
Implement a Six Sigma Control Plan that Drives
and Maintains Optimal Loop Management

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©2003 • ARC • 3 Allied Drive • Dedham, MA 02026 USA • 781-471-1000 • ARCweb.com
cost savings (greatly exceeding its energy saving) has come from turn-
around avoidance by eliminating unnecessary repairs. This alone
represents such a large savings opportunity that they are moving toward
adopting a RCM program. RCM combines the elements of reactive, pre-
ventative, and predictive maintenance while providing higher reliability at
a lower total cost. In essence, RCM examines the consequences of failure to
determine the appropriate maintenance requirements.
Workflow
Method Feature Comments
Reactive As needed
Low initial cost, no advanced failure warnings, can result in
production problems and high opportunity cost
Preventative
maintenance
Time based
Low initial cost, no advanced failure warnings, often perform
unnecessary maintenance, highest TCO
Predictive
maintenance
Condition
based
Need based maintenance, predicts failure, requires special
equipment, higher initial costs than preventive maintenance
– but lower TCO
Reliability
Centered
Combination
of above
Considers consequence of failure to determine appropriate
level of maintenance, lowest TCO, provides highest reliability
Maintenance Methodologies
Recommendations
• There is an enormous amount of unrealized performance remaining in
manufacturing assets. A best practice and continuous improvement
strategy is the best way to realize this performance. One prime area to
exploit is control loop performance.
• Manufacturers must adopt a comprehensive OpX program that pro-
vides a coordinated plan to perform maintenance on control loops to
ensure optimal performance and increase ROA. Since resources are
limited, it requires a sound maintenance strategy based upon knowl-
edge generated from a comprehensive surveillance program to indicate
the most economically beneficial opportunities.
Please help us improve our deliverables to you – take our survey linked to this
transmittal e-mail or at www.arcweb.com/myarc in the Client Area. For further
information, contact your account manager or the author at tfiske@arcweb.com.
Recommended circulation: All MAS-P clients. ARC Insights are published and
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