Large-Scale Controller Performance,Assessment, Diagnosis and Improvement

Mike PaulonisEastman Chemical Company

Presentation to: East TN AIChEFeb 2005

MAP 2005 2

Collaboration

Co-creator of controller performance assessment at Eastman

John Cox

MAP 2005 3

Agenda

Productivity – The Driver Circumstances Leading to Development System Overview Performance Assessment Details / Screenshots Application Results Summary

MAP 2005 4

Eastman productivity

Volume sold Employees

15 years ago

1 X 19,000

Today 2 X 12,000

Tremendous productivity gains (~ 8%/yr) !

MAP 2005 5

Sources of productivity

ProcessAutomation

InformationTechnology

ProcessImprovement

Morevolume

Fewerpeople

MAP 2005 6

A closer look at process automation

Generating productivity Enable stable plant operation at higher rates Enable a higher percentage of first-class product Enable plants to run safely with fewer operators

Affected by productivity changes

Year AdvCT employees

1993 17

1999 14

2005 11

MAP 2005 7

Increase in process control work on existing plants revealed many control loops with poor performance

Partial cause was a decrease in number and availability of personnel to monitor/troubleshoot control loops

Control loop/valve maintenance mode was “run until failure”

The need for a system to efficiently detect and diagnose poor control loops became apparent

Increase control engineer productivity Enable plant engineers to do more on their own

Focus on 1999

MAP 2005 8

More from 1999…

Honeywell introduced "Loop Scout" to general customers

The good: assess control loop performance from historical operating data

The bad: Cost: $350 per loop per analysis! Only accepted data from Honeywell control systems Have to send the controller data to Honeywell for

analysis

MAP 2005 9

We can do better (we think)

Our vision for controller performance assessment

Interfaces to all Eastman control and data systems Analyze thousands of loops automatically and

periodically Rank loop performance to quickly find opportunities Users can pull up current or historical performance of

any loop (interactive discovery) Users can get email reports on controller performance

specific to their plant (exception processing) Reports have summaries understandable by anyone

and details for in-depth analysis by control engineers Capture controller tuning changes which often link

with performance issues

MAP 2005 10

Read a lot of academic papers Implemented assessment algorithms in Matlab Tested/improved using real plant data Automated the capture of bulk data from control

systems Automated the analysis of bulk data Improved some more – hand tuned classification

algorithm from about 100 example loops Built a database to house all the analysis results

and service user queries Built a web application using Cold Fusion to bring

it all together and make it accessible to everyone

Build it!

MAP 2005 11

System architecture

Distributed data collection Distributed computing resources Server-side web programming Linked in to wide-area network

DCS 1App Host 1

w/Data Interface

User B

User A

File Server

Computation

Engine

Web Server

Email

System

DCS 2App Host 2

w/Data Interface

Database

LAN

MAP 2005 12

Eastman’s large-scale system

Ten sites Forty-nine process areas Interfaces to a variety of

control systems

Daily tuning history on 14,000 loops

Weekly performance history on 8,500 loops

MAP 2005 13

Use mode 1 - Tell me about a loop

MAP 2005 14

MAP 2005 15

Example help

MAP 2005 16

Use mode 2 - Find problem loops

MAP 2005 17

Find problem loops

Worst

Best

MAP 2005 18

Push content for busy people

Email subscription reports Monthly performance detail

Top 20 losers and gainers Rankings worst to best

Monthly performance summary Performance by loop type Performance by loop type over the last year Performance benchmark Eastman-wide

Daily tuning changes Notification - tuning changes often mean other

problems Monthly tuning detail

MAP 2005 19

Email examples

MAP 2005 20

Neat pictures, but does it really work?

Primary question around valve problems

Controller performance assessment showed many problems

Most seemed to be valve-related, not tuning

Valves need maintenance - culture change

Valve repair/replacement costs $$$

Don't want a lot of false positives on valve diagnoses

Open it 100%, OK, now close

it!

MAP 2005 21

Valve travel testing

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

50000

100000

150000

200000

250000

5 10 15 20 25

ValStat Valve Performance

Dis

tanc

e F

rom

Sea

t, [

inch

]

Fric

tion,

[ lb

f ]

Control Signal, [ ma ]

Increasing Signal Decreasing Signal *Friction

PROTUNER™

ValStat

MAP 2005 22

Polymer controller improvement project

Control Loop Diagnosis Repair

HR2 Spray Recirc Temp Hdw/sticking Add positioner

GR2 Spray Recirc Temp Hdw/sticking Add positioner

FR2 Spray Recirc Temp Hdw/sticking Add positioner

H MeOH Column Reflux Hdw/sticking Fix valve diaphragm

H MeOH Column Level Hdw/hysteresis Replace valve

J MeOH Column Level Hdw/unspecified Replace valve

F MeOH Column Level Hdw/sticking Engage positioner

DR2 Level Hdw/unspecified Repair positioner

C Paste EG Temp Hdw/sticking Repair positioner

HR1A Preht Dow Temp Hdw/sticking Replace valve

MAP 2005 23

Example performance improvement

MAP 2005 24

Second pass - entire classes

Reactor Dowtherm control valves all have motion problems (some up to 15% deadband)

Why? Long stem High-temp packing Dirty conditions No positioner

Solution? Critical service Replace all

A significant milestone!

MAP 2005 25

The trend looks good

New Dowtherm Valves

MAP 2005 26

Improvement in every category

December 2000 September 2002

MAP 2005 27

Beating the “competition”

December 2000

12th of 24 areas

50th percentile

September 2002

30th of 36 areas

83rd percentile

MAP 2005 28

The payoff (2001 vs. 2000)

Reduction in off-class production Reactor level - 272 klbs (80% reduction) Reactor temperature - 52 klbs (80% reduction) Vacuum - 119 klbs (35% reduction) Product specs - 96 klbs (35% reduction) 98.5% class 1 production - best ever

Reduction in startup and transition off-class 8.1 klb/startup (22%), 19.3 klb/transition (70%) Over 1 million lb/year - maybe 15-25% from control

Line run-life H-line best ever 222 days (9/10/01 - 4/19/02)

Customer complaints down 55%

MAP 2005 29

Controller Performance by Type(unfiltered)

40

45

50

55

60

65

70

75

80

Apr-0

0

Jul-0

0

Oct-

00

Jan-

01

Apr-0

1

Jul-0

1

Oct-

01

Jan-

02

Apr-0

2

Jul-0

2

Oct-

02

Jan-

03

Apr-0

3

Jul-0

3

Oct-

03

Jan-

04

Apr-0

4

Jul-0

4

Oct-

04

Co

mp

os

ite

Sc

ore Flow

Pressure

Level

Temperature

Long-term monitoring

Improve Maintain the gain Improve

MAP 2005 30

The bottom line

A revolution in knowledge for users of all levels Find problems that are not obvious Troubleshooting time reduced by 2/3 or more Monitor and benchmark performance over time

for continual improvement Enables effective approach to controller

maintenance Encourages communication between control

engineers, staff engineers, area managers, and maintenance forces

Generates significant economic gains

MAP 2005 31

Another example

Another polymers area embarked on a control improvement project in 2003 using performance assessment to identify opportunities and track results

Focused on problem loops critical to operation Added smart positioners to key valves Replaced some undersized valves Fixed some slave controller wind-up problems Implemented measurement filters where appropriate Did some control strategy redesign Much more…

MAP 2005 32

Great results!

MAP 2005 33

In search of excellence

MAP 2005 34

Other areas can do this too

Engineer signs up for monthly reports Engineer receives and reviews monthly reports

What is bad, what is good? Get management buy-in

Control loops need maintenance Controller performance is important

Engineer prioritizes loops Criticality, return on investment

Enlist help of CSM, E&I shops, Reliability Technology and AdvCT as needed

Engineer arranges funding and schedule for fix Engineer follows up to identify tangible

benefits

MAP 2005 35

Summary

Controller performance can be determined from historical operating data

Eastman's home-grown system does this weekly for thousands of controllers world-wide

Users can get performance information from a web site and/or have it emailed to them

With the system, work can quickly be focused on the best opportunities

Improved controller performance leads to improved process performance and greater profitability

We can now do much more with less