Modelling of a HIPPS with AltaRica
RAMS seminar 03.03.2017
Yun Zhang
Antoine Rauzy
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Issues
• Reliability assessment of complex system raises a
number of challenging issues:
–
–
–
–
How to design model efficiently?
How to reuse parts/components of models?
How to validate models?
How to have a quality assurance on the outputs of the modeling
process?
– How to maintain models throughout the life-cycle of systems?
– How to better integrate reliability engineering with other
disciplines? …
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Categories of modelling languages
Is there a generic/unified modeling framework to assess
reliability of complex systems?
Guarded Transitions Systems as implemented in AltaRica
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Problem statement
• We focus on modelling of a HIPPS with AltaRica
• The problem is mainly about
o how to design a maintenance model to help assessing condition
monitoring and optimization of maintenance policies given the
description of constraints
• But it could also be relevant for problems like
o how to analyze production of the system
o how to do risk analysis
o …
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System description
Logic solver (LS)
2oo3
1oo2
Shut down valves (SDV)
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Sensors (S)
5
Features of the HIPPS
• Components:
– Continuously monitored components (logic solver and sensors)
– Periodically tested components (shutdown valves)
• Objectives:
– Reduce number of maintenance interventions
– Minimize system downtime
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Step 0. Block diagram
S
S
S
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SDV
LS
SDV
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Step 1. Repairable component
W
F
Logic solver (LS)
2oo3
1oo2
Sensors (S)
Shut down valves (SDV)
W
F
W
F
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W
F
W
F
W
F
8
Finite state automaton for repairable
component
failure
_state = WORKING
_state = FAILED
repair
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Step 2. Tested component
W
F
Logic solver (LS)
2oo3
1oo2
Sensors (S)
Shut down valves (SDV)
W
F
W
F
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W
F
W
F
W
F
10
Finite state automaton for a tested
component
repair
_state = WORKING failure
_state = FAILED_UNDETECED
_phase = OPERATION
_ phase = OPERATION
_state = FAILED_DETECTED
_ phase = OPERATION
OPERATION
PHASE
startTest
TEST
PHASE
completeTest
_state = WORKING
_phase = TEST
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startTest
completeTest
_state = FAILED_UNDETECTED
_phase = TEST
startTest
completeTest
_state = FAILED_DETECTED
_phase = TEST
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Step 3. Periodic maintenance
1PT/month
W
F
OP
0
Logic solver (LS)
OP
PT
OP
PT
PT
MT
2oo3
1oo2
Sensors (S)
Shut down valves (SDV)
W
1MT/year
F
W
F
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W
F
W
F
W
F
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Finite state automaton for a monitored
component
_state = FAILED_DETECTED
_phase = MAINTENANCE
_state = WORKING
_phase = MAINTENANCE
MAINTENANCE
PHASE
startMaintenance
OPERATION
PHASE
completeMaintenance
_state = WORKING
_phase = OPERATION
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failure
startMaintenance
_state = FAILED_DETECTED
_ phase = OPERATION
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Finite state automaton for a tested
component
_state = WORKING
_phase = MAINTENANCE
MAINTENANCE
PHASE
startMaintenance
OPERATION
PHASE
TEST
PHASE
completeMaintenance
_state = WORKING
_phase = OPERATION
startTest
_state = FAILED_UNDETECTED
_phase = MAINTENANCE
startMaintenance
failure _state = FAILED_UNDETECTED
completeTest
_state = WORKING
_phase = TEST
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_ phase = OPERATION
startTest
completeTest
_state = FAILED_UNDETECTED
_phase = TEST
_state = FAILED_DETECTED
_phase = MAINTENANCE
startMaintenance
_state = FAILED_DETECTED
_ phase = OPERATION
startTest
completeTest
_state = FAILED_DETECTED
_phase = TEST
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Step 4. Condition based maintenance
W
F
Logic solver (LS)
2oo3
1oo2
Sensors (S)
Shut down valves (SDV)
W
F
W
F
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W
F
W
F
W
F
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Our knowledge about the state of the system maybe different from
actual state of the system…
HIPPS
Controller
Sensors
S
S
S
LS
S
S
S
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Actuators
SDV
SDV
SDV
LS
SDV
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working
State at different levels
degraded
System working
failed
System level
HIPPS
Controller
Sensors
S
S
S
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LS
Actuators
SDV
SDV
Sub-system level
component level
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working
State at different levels
degraded
System working
failed
System level
HIPPS
Controller
Sensors
S
S
S
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LS
Actuators
SDV
SDV
Sub-system level
component level
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working
State at different levels
degraded
System working
failed
System level
HIPPS
Controller
Sensors
S
S
S
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LS
Actuators
SDV
SDV
Sub-system level
component level
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working
State at different levels
degraded
System degraded
failed
System level
HIPPS
Controller
Sensors
S
S
S
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LS
Actuators
SDV
SDV
Sub-system level
component level
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working
State at different levels
degraded
System failed
failed
System level
HIPPS
Controller
Sensors
S
S
S
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LS
Actuators
SDV
SDV
Sub-system level
component level
21
working
State at different levels
degraded
System failed
failed
System level
HIPPS
Controller
Sensors
S
S
S
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LS
Actuators
SDV
SDV
Sub-system level
component level
22
working
State at different levels
degraded
System failed
failed
System level
HIPPS
Controller
Sensors
S
S
S
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LS
Actuators
SDV
SDV
Sub-system level
component level
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Component states
Components
S1
working
failed detected
S2
working
failed detected
S3
working
failed detected
LS
working
failed detected
SDV1
working
failed undetected
failed detected
SDV2
working
failed undetected
failed detected
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Sub-system states
Sub-system
working
degraded
failed
Sensors
3 working
2 working
1 or 0 working
Logic solver
1 working
Shutdown valves
2 working
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0 working
1 working
0 working
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System states
System
working
degraded
failed
Sensors
(and) working or
degraded
(and) degraded
(or) failed
Logic solver
(and) working
(and) working
(or) failed
Shutdown valves
(and) working or
degraded
(and) degraded
(or) failed
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Finite state automaton for decision rules
condition=working
_phase=operation
OPERATION
condition=degraded
_phase=operation
condition=failed
_phase=operation
completeTest [1] startTest [1439] completeTest [1] startTest [1439]
condition=degraded
_phase=test
condition=working
_phase=test
TEST
condition=failed
_phase=test
condition!=working?
startMaintenance [0]
completeMaintenance [24]
condition=degraded
_phase =
maintenance
MAINTENANCE
completeTest [1] startTest [1439]
condition!=working?
startMaintenance [0]
condition=failed
_phase=
maintenance
completeMaintenance [24]
command  {operation, test, maintenance}
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condition  {working, degraded, failed}
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