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Agenda. Alarm Management and Analysis ? Definitions and MisconceptionsPurpose of an AlarmWhat is Alarm Management?Can I buy an Alarm Management System?What is Alarm Management?What is Alarm Analysis?Update on EEMUA and ISA developmentsWhat is EEMUA?What is ISA 18.02? - Alarm Management Life
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1. Management and Abnormal Situation Solutions Alarm Analysis and Management Overview
Apr 27, 2009
DC ISA
Presenter; Guillermo Abreu
Emerson Product Manager
2. Agenda Alarm Management and Analysis Definitions and Misconceptions
Purpose of an Alarm
What is Alarm Management?
Can I buy an Alarm Management System?
What is Alarm Management?
What is Alarm Analysis?
Update on EEMUA and ISA developments
What is EEMUA?
What is ISA 18.02? - Alarm Management Life Cycle.
Alarm Analysis Purpose; Why do we need Alarm Analysis?
What data is essential for Alarm Analysis?
Outcome of Alarm Analysis
Alarm Activity Analysis
Alarm Flood Analysis
Frequent Alarms Analysis
Chattering Alarm Analysis
Long Standing Alarm Analysis
Alarm Distribution Analysis
Correlated Alarm Analysis
Configuration Analysis
Approach to use Analysis Results with the alarm Life Cycle
Additional Tips for improving an Alarm System.
Questions
3. Purpose of an Alarm. To effectively convey trouble areas to operators without causing them to become confused or overwhelmed and advise them that action is required
4. Alarm ManagementWhat is it? Alarm management is the process to properly design, implement, operate and maintain alarms in a plant.
Alarm Management is a process, not a project.
5. Can I buy an Alarm Management System? No
Alarm Management in a process not a project
Artificial intelligence solutions not yet available.
What alarms require?
Careful Planning
Rationalization
Installation
Verification/ Audits
Maintenance
Training
6. What is Alarm Analysis? Is a statistical tool to help measure the alarm system performance and provide insight information to uncover potential areas of improvement.
It also help benchmark system performance with industry guidelines to measure effectiveness.
If the adage you can not manage what you can not measure holds true, Alarm Analysis becomes an integral part of alarm management to provide feedback on improvement initiatives and measure the overall effectiveness of the process / program.
7. What is EEMUA? Stands for: The Engineering Equipment and Materials Users' Association
European based non-profit industry Association
Aims to improve the safety, environmental and operating performance of industrial facilities in the most cost-effective way.
Published; 191 Alarm Systems - A Guide to Design, Management and Procurement
Updated in 2007; (2nd Edition) with field proven information.
Leverage information from the ASM Consortium, Industry Studies, Incident Analysis.
Website Resources Referenceshttp://www.eemua.co.uk
Great Benchmarking info like activity rates, risk management (prioritization), Total alarm installed.
Operators questionnaires to access usefulness of the alarm system and guide improvements.
Resource to rationalization and analysis techniques.
Overall a great guide that has been deemed the defacto standard for alarm management
8. What is ISA 18.02? Management of Alarm Systems for the Process Industries.
Is ISA effort to develop a standard to provide a blueprint for developing an effective alarm management strategy.
It wont tell automation suppliers how to design their alarm system but it provides guidance to help them put together solutions to allow end users to design their own alarm management strategy.
Outlines best practices for both existing and new facilities.
It is expected that the next generation of Alarm solutions will provide more metrics and improved identification of floods, chatters to provide users quicker access to the date they need.
ISA 18.02, is expected to be approved in the summer 2009
Prescribes a life Cycle based approach to managing alarms
9. Alarm Management Life Cycle
10. What is the Alarm Analysis Purpose?
11. What Data is essential for Alarm Analysis Date and Time of Events
Tag Name
Tag Type
Descriptions
Event Priority
Event Type (high Alarm, trip, failed)
Operator Action (Acknowledged, Return)
Value exceeded
Plant Area Code (optional)
Reporting Node (optional)
This data is obtained by different methods like OPC Alarm and Event Servers, printer ports or manufacturer specific publishing server (via an API).
12. Outcome of Alarm Analysis. Alarm Activity Analysis Average rate good indicator of the system health.
Unusual high activity levels are plotted in trend charts
Excessive events can be the result from abnormal conditions
150 alarms per day are considered acceptable per the EEMUA guidelines
Over 300 are considered manageable
Anything outside of these metrics exposes the kind of load on the operator, which compromises safety and efficiency.
Measuring on an hourly basis can be quite effective in monitoring the alarm system performance .
Measuring alarms in a 10 min period can effectively identify the beginning of floods. Eg. 10 alarm in 10 minutes.
Additional activity parameters that are useful.
Days with max and min activity
Top Activity days
Percent of totals and accumulated percents
Alarms per hour, per shift, per day and per 10 minutes period with average max and min
Average alarm per hour for different priorities
Averages per hour with minimum and maximum
13. Alarm Floods Analysis Determine periods of activity where the rates of alarm are higher than the operator can handle.
During these periods alarms become a nuisance and a distraction.
Important alarms can be easily missed.
Calculations involves measuring how long the system produces alarms above a maximum rate. Eg. 10 alarms in 10 minutes. Also a minimum rate is defined to end the flood period. Eg. 5 alarms in 10 minutes.
Additional data from flood events can include:
Number of floods per day / week
Total Duration of all floods
Start / Stop Time of each flood
Flood Severity. - how many alarms during flood (Top Ten flood events during the period)
Percentage of time the alarm system is in a flood condition.
14. Frequent Alarms Analysis A relative few signals often product a large percentage of alarms.
Frequent alarm analysis helps expose those signals
Substantial performance improvement can be gained by addressing these signals first.
These signals include nuisance alarms which are suspect and cant be relied upon.
Potential hazardous situations can result when operators do not trust the validity of alarms.
Often 10 to 20 of the most frequent alarms produce between 20 to 80 percent of all the alarms.
A common practice is to suppress nuisance alarms, but this approach without proper rationalization can result a high volume of non annunciated alarms which can have hazardous consequences with financial losses, safety and environmental impact.
Additional useful information from this analysis is:
Number of occurrences
Tag Names and Description
Priority of the Alarms
Percent of total and Accumulated Percentage
15. Chattering Alarm Analysis These are alarms that transition in and out in short amount of time
The time and rate must reflect what is considered too fast for an operator to take action. Eg. 3 occurrences in 1 minute
It is common for a chattering alarm to produce hundreds of alarms in a few hours.
Very big distraction for operators and can cause periods of flood.
The may reflect;
Instrument problems
Poor control
Bad dead bands
Improper delay settings
Chattering alarms are easily fixed and should not be ignored.
Information of the chatter analysis that is useful to correct the problem:
Top Ten Chattering signals
Total alarms due to chatter
Percentage of total alarms due to chatter.
16. Long Standing Alarm Analysis These are alarms that the operator does not pay attention to.
They provide little value to the operator
More than 24 Hours is a good Time windows to measure standing alarms
The Analysis provides a list of alarms that should be candidates for rationalization and possible suppression under certain conditions.
Other Information that is useful from this analysis:
Top Ten standing Alarms signals
Time Standing
Number of Active Alarms per Hour
Open Alarms in period with Min and Max
17. Alarm distribution Analysis (priority and others) Distribution analysis by priority provides indication that the alarm system may not be rationalized correctly.
EEMUA has recommendations on priority distribution.
Alarm priority represents risk management into the system and can compromise safety and efficiency.
Too many high and medium priority alarms can overwhelm operators during upsets making it hard to distinguish the importance of the alarm.
The priority distribution can vary significantly between configuration and occurrence.
Other Distributions analysis that can be useful:
Alarms by Regions
Alarms by Signal Type
Alarm by Event Types (High, Low etc)
Alarm by control node
18. Correlated Alarm Analysis This is also called parent/child analysis and cause/consequence analysis
During period (1 day or week) a time window (eg. 60 secs) when a parent alarm occurs is specified for the child to occur, if this happens for a number of times they are probabilistically considered correlated.
Identify alarms that are closely linked and may convey the same information. Alarms with the same root cause
High alarms and high high alarms can be correlated if the settings are too close together.
19. Configuration Analysis. Provide information about how the alarm system is configured.
Number of alarms installed
How many alarms per priority, region, type, node
Total alarms from instruments
Alarms from the control system (generated)
These are generally good statistics to compare with the Analysis resulting from the actual events which are supposed to yield understandable results.
Eg. If the system produces large amount of high priority alarms, the configuration analysis can reveal the percentage of high priority alarms installed. This in turn can uncover if the system is dangerously operated or simply wrongly configured.
20. Approach to use Analysis results with life cycle
21. Additional tips for Improving an Alarm System Re-evaluate priorities from time to time.
Reduce standing alarms
Identify and resolve implementation issues
Create an alarm management team to review alarm management strategies
Continuous training on new/changed alarms is the key to obtain excellent operational results.
Uncover new areas of improvement to achieve higher levels of performance.
Do not assume that all trip points and limits are correct, review from time to time to make sure they have not changed
Keep an eye on any new projects (links integration, system modifications etc.) for excessive alarming.
When an alarm is removed, use another method for situation awareness, e.g.. Graphics.
22. Alarm AnalysisQuestions, Suggestions, Rumors?