The Top 10 Worst Performing Alarm Systems in Industry

Transcription

1 The Top 1 Worst Performing Alarm Systems in Industry Bill Hollifield Principal Alarm Management Consultant Mary Kay O Connor O Process Safety Symposium October 26

2 The Source of The Data PAS: Benchmarking alarms systems since 1994 Hundreds of alarm projects, all around the world Overloaded and poorly performing DCS alarm systems are common, and proven to be contributing factors in several major accidents Examples of very severe problems Possible solutions to the problems identified are discussed in the accompanying paper and in The Alarm Management Handbook Alarms Per Operator Position Configured The Top 1 Worst Performing Alarm System in Industry PAS 26. Page 2

3 Number 1: Worst Diagnostic Alarm Percentage Alarm Count - 24 Days Annunciated Alarms by Type These three alarm types, indicating instrument malfunction, made up 71% of all alarm events in a 24-day period Cumulative % System is dominated by Instrument Malfunction Alarms 71% of all alarm events A common situation All can be fixed Common configuration problems IOBAD BAD_S BAD_P STATE RANGE LOABS HIABS All Others Should not be tolerated Solution: Explain to Control Engineers it is NOT OK NOT OK that $,$$$,$$$ worth of instruments do not work much of the time The Top 1 Worst Performing Alarm System in Industry PAS 26. Page 3

4 Number 9: Worst Nuisance Alarm Percentage Alarm Count Top 1 Most Frequent Annunciated Alarms Cumulative % 98% of all alarm events come from 1 alarms! Normal situation is 2% to 8%! All can be fixed MV22.BADPV 43MV6.BADPV 43MV24.BADPV 43PAH397.OFFNRM 43MV1.BADPV 43MV18.BADPV 43MV22.CMDDIS 43MV1.CMDDIS 43MV18.CMDDIS 43FC155.PVLO Design Goal? Create alarms that go off hundreds or thousands of times per day. Solution: Alarm Bad Actor Resolution Process (Easy, fast, and cheap.) The Top 1 Worst Performing Alarm System in Industry PAS 26. Page 4

5 Number 8: Worst Alarm Suppression - Alarms Per Day - 4 All Recorded Alarms EEMUA 'Managable' (3) Annunciated Alarms Alarm Suppression 98% of all alarm events have been suppressed Lack of Management-ofchange 5-18 Days- Uncontrolled Alarm Suppression is a highly hazardous situation. Solution: Alarm Audit & Enforcement, and Proper Alarm Shelving The Top 1 Worst Performing Alarm System in Industry PAS 26. Page 5

6 Number 7: Worst Alarm Priority Distribution 1% Alarm Priority Low High Emergency Far too many higher-priority alarms Percentage 9% 8% 7% 6% 5% 4% 3% 2% 1% % 8% 15% EEMUA 5% 8% 19% 1% Annunciated Alarms System is ineffective at providing truly useful guidance to the operator Devalues the importance of higher priority alarms Solution: Alarm Rationalization The Top 1 Worst Performing Alarm System in Industry PAS 26. Page 6

7 Number 6: Worst Daily Alarm Rate (Including Suppressed) - Alarms Per Day Peak: 48,83 All Recorded Alarms Annunciated Alarms EEMUA 'Managable' (3) Average: 26,665 Alarm Suppression Average 1 alarm every 3 seconds Peak >1 every 2 seconds -18 Days- Solution: Combine the prior solutions The Top 1 Worst Performing Alarm System in Industry PAS 26. Page 7

8 Number 5: Worst Daily Annunciated Alarm Rate Annunciated Alarms Per Day Annunciated Alarms Annunciated Alarms without 1 Most Frequent 'Manageable' (3/day) Average 1 alarm every 8 seconds Peak 1 alarm every 4 seconds Eliminating only 1 different alarms makes a huge difference - 42 Days - Another highly overloaded alarm system a hindrance rather than a help. Solution: Combine the prior solutions The Top 1 Worst Performing Alarm System in Industry PAS 26. Page 8

9 Number 4: Worst Annunciated Alarm Burst Rate Annunciated Alarms per 1 Minutes Peaks exceeding 5 alarms in 1 minutes Highest 1- minute Rate = 3517 Alarm Flood = 1+ in 1 minutes A Peak of 3,517 alarms in a 1 minute period! More than 1 alarms in 1 minutes results in operator alarm load shedding Important alarms are likely to be overlooked - Analysis Period 12 days - Solution: Add in State-Based Alarming and Alarm Flood Suppression to the prior solutions The Top 1 Worst Performing Alarm System in Industry PAS 26. Page 9

10 Number 3: Worst Average Time-In-Flood Percentage Alarm Floods - Alarm Count Peaks Range from 3+ to 2,+ 51 Separate Floods Highest Count in an Alarm Flood = 215,313 Longest Duration of Flood = Hours - 42 Days - Alarm Systems in flood have little protective capacity and interfere with managing an abnormal situation Alarm Flood Analysis: Number of Floods Floods Per Day Total Alarms in All Floods Average Alarms per Flood Highest Alarm Count in a Flood Percentage of Alarms in Floods vs. All Annunciated Alarms Total Duration of Floods, in Hours Percentage of Time Alarm System is in a Flood Condition ,311 5, , % % The Top 1 Worst Performing Alarm System in Industry PAS 26. Page 1

11 Number 2: Longest Alarm Flood Duration in Hours Alarm Floods - Duration Peaks exceed 1 hours 134 Separate Floods Longest Duration of Flood = Hours containing 373,719 alarms Longest Flood: 4.4 days with over 37, alarms Average rate during flood: 2,2 alarms per hour, or 37+ alarms per 1 minutes Alarm Systems in flood have little protective capacity and interfere with managing an abnormal situation Days - Solution: Add in State-Based Alarming and Alarm Flood Suppression to the prior solutions The Top 1 Worst Performing Alarm System in Industry PAS 26. Page 11

12 Number 1: The Worst Single Alarm Annunciated Alarms per 1 Minutes From a Single Low-Pressure Alarm Highest 1-minute Rate = Hours - A low pressure alarm from an pressure controller (analog signal, not a switch) >2, alarms in a day, or 142 per minute A Single-day peak on this system of 28,311 alarms Wow! But one more. Solution: Alarm Bad Actor Resolution The Top 1 Worst Performing Alarm System in Industry PAS 26. Page 12

13 Bonus: The Highest Sustained Alarm Rate Ever Alarms Per Day Highest Sustained Alarm rate Ever Recorded Peak: 18,488 Alarms in a Day Average: 173, Days - DCS loading and performance problems can result from high alarm rates! Newly installed Safety Instrumented System (SIS) with grounding problems Alarms configured to not be seen by the operator just historized. Found only through PAS Alarm Analysis software Average: 173,657 alarms per day Peak: 18,488 alarms per day (more than 2 per second) Solution: Monitor your alarms The Top 1 Worst Performing Alarm System in Industry PAS 26. Page 13

14 Seven Steps to Highly Effective Alarm Management Step 1: Develop, Adopt, and Maintain an Alarm Philosophy Always Needed Step 2: Collect Data and Benchmark Your Systems Step 3: Perform Bad Actor Alarm Resolution Step 4: Perform Alarm Documentation and Rationalization (D&R) Step 5: Implement Alarm Audit and Enforcement Technology Step 6: Implement Real Time Alarm Management Often Done Simultaneously Needed Based Upon Performance Step 7: Control and Maintain Your Improved System The Top 1 Worst Performing Alarm System in Industry PAS 26. Page 14

15 Summary Overloaded and malfunctioning alarm systems are common throughout industry. Poor alarm systems negatively impact the profitability, safety and environmental performance of processing plants worldwide. The problems can be identified, isolated, and solved through proven alarm management methodologies. The Top 1 Worst Performing Alarm System in Industry PAS 26. Page 15