Title: Management and Abnormal Situation Solutions Alarm Analysis and Management
1Management and Abnormal Situation Solutions
Alarm Analysis and Management
- Overview
- Apr 27, 2009
- DC ISA
- Presenter Guillermo Abreu
- Emerson Product Manager
2Agenda
- 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
3Purpose 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
4Alarm 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.
- 30 Thousand Alarms are not uncommon in a plant
- What about a company with a fleet of process
plants - Because plants adopt their own personalities as
they age alarm causes can be unique. - Institutional knowledge affects operations when
personnel turnovers occur. When this happens
safety and efficiency are compromised. - The problem becomes even greater, with digital
systems when it can be justified logically that
the more alarms the more safe the system becomes.
5Can 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
6What 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.
7What 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
8What 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
9Alarm Management Life Cycle
10What is the Alarm Analysis Purpose?
- Looking at the ISA 18.02 life cycle approach,
Alarm Analysis plays an important role in
monitoring, assessing and auditing the Alarm
management system.
- What can we do with Alarm Analysis?
- Find alarms that do not function correctly
- Performance metrics
- Alarm Activity / Rates
- Frequent Alarm (bad Actors)
- Isolate and Analyze individual plant areas
- Analyze Plant upset or Alarm Flood
- Priority Distribution of Alarms
- Stale / Long Lasting Alarms
- Chattering Alarm
- General statistics on Alarms
- Performance Metrics with Industry guidelines
(EEMUA)
11What 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).
12Outcome 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
13Alarm 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.
14Frequent 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
15Chattering 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.
16Long 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
17Alarm 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
18Correlated 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.
19Configuration 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.
20Approach to use Analysis results with life cycle
- If the Alarms system is new is recommended to
follow the life cycle approach proposed by the
ISA 18.02 standard (Draft) - On existing systems two different approaches may
be used to properly utilize Alarm Analysis
Results - Short term (Sanity Actions)
- Most Frequent Alarms root cause Analysis
- Chattering Alarms Elimination
- Standing points review and redesign. (possible
suppression). - Review alarm correlations and implement possible
corrections to abnormal issues. - Long Term
- Update or Create an Alarm philosophy
- Reevaluate and Rationalize all the alarms for
effectiveness and risks (priorities) - Design and implement changes identified gaps
identified in the philosophy and rationalization
steps. - Fully establish the Monitoring, Change Management
and Auditing Procedures to ensure proper
management
21Additional 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.
22Alarm AnalysisQuestions, Suggestions, Rumors?