Practical Benefit of Risk Assessment: Zone Determination by Layout Analysis Mark Nehrkorn Director RCC Safety SICK Inc.
Practical Benefit of Risk Assessment: Zone Determination by Layout Analysis
What is a Zone? • A zone may include space within or around the system: • which is used by personnel to access a specific location, an operating position or a servicing point; • in which personnel perform standard production operations or other tasks.
Types of Zones • zone: a segmented space within a machine • control zone: An identified portion of a production system under coordinated control • hazard zone: Any space within or around a machine in which a person can be exposed to a hazard in which an immediate or impending hazard exists • task zone: Any predetermined space within or around a machine in which a person can perform work
Definition Sources: ISO11161:2007, ANSI B11.19-DRAFT #8, ANSI B11.20 – DRAFT #7
Why Create Zones? • Automation systems should be designed to facilitate safe manual interventions
Set-Up
Operation
Troubleshooting
Maintenance
• For some manual interventions, it may be impractical to stop the whole system • … in which case the system should be segregated into zone(s) where personnel can perform their tasks safely
Where is Guidance Available? • ANSI/RIA R15.06-2012, Part 2 (ISO 10218-2:2011) • 5.9 Integrated manufacturing system (IMS) interface • 5.9.1 General • 5.9.2 Emergency stop • 5.9.3 Safety-related parts of the IMS • 5.9.4 Local control • 5.9.5 Enabling device • 5.9.6 Mode selection • 5.9.7 Task zone implementation
Where is Guidance Available? • ISO 11161:2007 + Amd 1:2010 • Safety of machinery — Integrated manufacturing systems — Basic requirements
• ANSI B11.20-2004 (R2015) • Safety Requirements for Integrated Manufacturing Systems
Interrelationship of Standards • • •
•
This figure describes the relationship of the scope of machinery standards used in a robot system The robot alone is covered by Part 1, the system and cell is covered by Part 2 A robot cell may include other machines subject to their own C level standards, and the robot system can be part of an integrated manufacturing system covered by ISO 11161 which in turn can also make reference to other relevant B and C level standards Part 2 adds additional information in line with ISO 12100 and ISO 11161
ISO 10218-1
ANSI/RIA R15.06 (Part 1) Robot
ISO 10218-2
Robot system/cell
ISO 11161 ISO 12100
Integrated Manufacturing System (IMS) RISK ASSESSMENT
Source: ANSI/RIA R15.06, Part 2, Figure 1
ANSI/RIA R15.06 (Part 2) Other machine (C-type) standard
ANSI B11.20 RIA R15.306 & ANSI B11.0
Interrelationship of Standards
Image Source: ANSI/RIA R15.06, Part 2, Annex B
Integrated Manufacturing Systems • An integrated manufacturing system (IMS): a) incorporates two or more industrial machines which: 1) can operate independent of each other, and 2) are intended for the purpose of manufacturing, treatment, movement or packaging of discrete parts or assemblies;
b) is linked by a material handling system; and c) is interconnected by a control system(s) for coordinated operation Gate lock cylinder
Butt shear (saw)
Platen
Die carrier
Span of Control • span of control: Predetermined portion of the production system under control of a specific device • The control of one or more control zones of the machine by various safety-related control devices is defined by the span of control of each device
Definition Source: ISO11161:2007, ANSI B11.19-DRAFT #8, ANSI B11.20 – DRAFT #7
Devices with Span of Control • Typical safety-related control devices which may have span of control include: • INPUT: • Safeguarding devices: o Interlock devices o Presence sensing devices
• OUTPUT: • End switching devices: o Contactors o Valves o Drives
• Complimentary control devices: o Emergency stops o Enabling devices o Hold-to-run controls o Resets
Span of Control & Layout Analysis • Additional guidance in future machine-specific (Type-C) ANSI standards: • The span of control of safety-related control devices shall be determined by a layout analysis, which includes: • • • • •
Specification of the limits Task/hazard pairs as identified from a risk assessment Task zone identification Selecting risk reduction measures Control zone identification
Risk Assessment Process
Image Source: ANSI B11.0-2015, Figure 6 (Used with permission) Referenced by RIA TR R15.306-2016, Clause 6
Layout Analysis Process
Image Source: ANSI B11.20-DRAFT #7
Comparison of Processes
Combination of Processes
Risk Assessment Process
Layout Analysis Process
Applying Layout Analysis to an Example Risk Assessment
Risk Assessment Example • Palletizing Cell
Risk Assessment Example • Identification of Tasks B
A
A: Load/Unload Pallets
F2
B: Cleaning
F1
C: Teaching Robot
F1
D: Jam Clearing
F2
E: Conveyor Maintenance
F1
1) task: specific activity performed by one or more persons on, or in the vicinity of, the machine during its life cycle 2) task: Any specific activity that is done with, on or around the machine during its lifecycle.
D Definition Sources:
E 1) ISO 12100-1:2010 2) ANSI B11.0-2015
D
C
B
A
Risk Assessment Example • Identification of Hazard Sources 1: Robot / End Effector
F2
2: Conveyor Lifts
F1
3: Conveyors
F1 F2 F1
hazard: A potential source of harm
2 Definition Sources:
3 ISO 12100-1:2015, ANSI B11.0-2015
2
1
Risk Assessment Example • Identification of Hazard Types 1: Robot / End Effector
2: 1a: Conveyor Crushing Lifts
S3
3: 1b: Conveyors Dropped parts
S1
2: Conveyor Lifts 2a: Shearing
S4
2b: Pinching
S2
2c: Entanglement
S3
3: Conveyors 3a: In-running nip points
2 Definition Sources:
3 ISO 12100-1:2015, ANSI B11.0-2015
2
1
S2
Risk Assessment Example • Identification of Task Zones
I:
I
Load/Unload & Cleaning
II: Teaching Robot III: Jam Clearing IV: Maintenance
task zone: Any predetermined space within or around a machine in which a person can perform work
III Definition Sources:
IV
III
ISO11161:2007, ANSI B11.19-DRAFT #8, ANSI B11.20 – DRAFT #6
II
I
Risk Assessment Example HAZARDS
• Risk Assessment: Identify Task / Hazard Pairs
TASKS
ROBOT
CONVEYOR LIFTS
CONV.
1a
1b
2a
2b
2c
3a
Crushing
Dropped Parts
Shearing
Pinching
Entang.
In-Running Nips
A
L/UL
1
2
-
-
-
-
F2
B
Cleaning
3
4
-
-
-
-
F1
C
Teaching
5
6
-
-
-
-
F1
D
Clearing
7
8
9
10
11
12
F2
E
Maint.
13
14
15
16
17
18
F1
S3
S1
S4
S2
S3
S2
Risk Assessment Example • Risk Assessment: Risk Estimation ID
Task
Haz-ard
Sever-ity
Exposure
Avoidance
Occurrence
Risk Level
PLr
1
A
1a
S3
F2
A1
O2
4
d
2
A
1b
S2
F2
A2
O2
1
b
3
B
1a
S3
F1
A1
O1
1
b
4
B
1b
S2
F1
A2
O1
0
a
5
C
1a
S3
F1
A1
O3
3
c
6
C
1b
S2
F1
A2
O1
0
a
7
D
1a
S3
F2
A1
O1
3
c
8
D
1b
S2
F2
A2
O1
0
a
9
D
2a
S3
F2
A2
O2
6
d
10
D
2b
S1
F2
A2
O2
0
a
11
D
2c
S2
F2
A2
O2
1
b
12
D
3a
S1
F2
A2
O2
0
a
13
E
1a
S3
F1
A1
O1
1
b
14
E
1b
S2
F1
A2
O1
0
a
15
E
2a
S3
F1
A2
O2
3
c
16
E
2b
S1
F1
A2
O2
0
a
17
E
2c
S2
F1
A2
O1
0
a
18
E
3a
S1
F1
A1
O2
0
a
Risk Assessment Example • Control Zones for Coexistence
A Zone B Control ZoneControl
Control Zone C
Risk Assessment Example • Apply Protective Measures (Gap in the Fence)
Safe! But not very efficient…
Risk Assessment Example R R
R
R
R
R
Risk Assessment Example • Safety-Related Span of Control Control Zone C
R R
A Zone B Control ZoneControl
R
R
R
R
Risk Assessment Example • Risk Assessment: Risk Reduction Measures Task
Hazard
Severity
Exposure
Avoidance
Occurrence
Risk Level
PLr
1
A
1a
S3
F2
A1
O2
4
d
Interlocked sliding door, Light curtain, Awareness light, Reduced robot speed controlled by Area scanner
2
A
1b
S2
F2
A2
O2
1
b
Interlocked sliding door, Light curtain
3
B
1a
S3
F1
A1
O1
1
b
Interlocked sliding door, Light curtain, Awareness light, Reduced robot speed controlled by Area scanner
4
B
1b
S2
F1
A2
O1
0
a
Interlocked sliding door, Light curtain
5
C
1a
S3
F1
A1
O3
3
c
Teach pendant (with enabling device and emergency stop), Manual reduced speed (T1)
6
C
1b
S2
F1
A2
O1
0
a
Teach pendant (with enabling device and emergency stop), Manual reduced speed (T1)
7
D
1a
S3
F2
A1
O1
3
c
Interlocked hinged door, Infeed light curtain, Interlocked sliding door, Emergency stop cable pull, Safe distance, Awareness signs
8
D
1b
S2
F2
A2
O1
0
a
Interlocked hinged door, Infeed light curtain, Interlocked sliding door, Safe distance, Awareness signs
9
D
2a
S3
F2
A2
O2
6
d
Interlocked hinged door, Infeed light curtain, Interlocked sliding door, Emergency stop cable pull, Safe distance, Awareness signs
10
D
2b
S1
F2
A2
O2
0
a
Interlocked hinged door, Infeed light curtain, Interlocked sliding door, Emergency stop cable pull, Safe distance, Awareness signs
11
D
2c
S2
F2
A2
O2
1
b
Interlocked hinged door, Infeed light curtain, Interlocked sliding door, Emergency stop cable pull, Safe distance, Awareness signs
12
D
3a
S1
F2
A2
O2
0
a
Interlocked hinged door, Infeed light curtain, Interlocked sliding door, Emergency stop cable pull, Safe distance, Awareness signs
13
E
1a
S3
F1
A1
O1
1
b
Control of hazardous energy (lockout/tagout), Safe work procedures
14
E
1b
S2
F1
A2
O1
0
a
Control of hazardous energy (lockout/tagout), Safe work procedures
15
E
2a
S3
F1
A2
O2
3
c
Control of hazardous energy (lockout/tagout), Safe work procedures
16
E
2b
S1
F1
A2
O2
0
a
Control of hazardous energy (lockout/tagout), Safe work procedures
17
E
2c
S2
F1
A2
O1
0
a
Control of hazardous energy (lockout/tagout), Safe work procedures
18
E
3a
S1
F1
A1
O2
0
a
Control of hazardous energy (lockout/tagout), Safe work procedures
ID
Risk Reduction Measures: Technical Protective Measures & Administrative Measures
Risk Assessment Example
Risk Assessment Example SAFETY-RELATED COMPONENTS HIGHEST LEVEL OF SAFETY PERFORMANCE • Interaction Matrix (Performance Levels and Span of Control)
AUXILIARY
RESET
EMERGENCY STOP
PROTECTIVE STOP
FUNCTION
DEVICE
LOCATION
ROBOT
CONVEYOR LIFTS
CONVEYORS
Light Curtain
Conveyor Entrance
d
d
b
Door Interlocks
Lift Doors
d
d
b
Door Interlocks
L/UL Doors
d
d
b
Door Interlock
Maintenance Door
d
d
b
Light Curtains
L/UL Stations
d
-
-
Area Scanners
L/UL Stations
d
-
-
Position Switches
Robot Primary Axes
d
-
-
E-stop Pushbutton
Conveyor Entrance
b
b
b
E-stop Pushbuttons
Lift Doors
b
b
b
E-stop Pushbuttons
L/UL Doors
b
b
b
E-stop Pushbutton
Maintenance Door
b
b
b
E-stop Cable Pull
Cell Interior
b
b
b
Reset Pushbutton
Conveyor Entrance
d
d
a
Reset Pushbuttons
Lift Doors
d
d
a
Reset Pushbuttons
L/UL Stations
d
d
a
Reset Pushbutton
Maintenance Door
d
d
a
Muting Sensors
Conveyor Entrance
d
d
b
Mute Override
Conveyor Entrance
d
d
b
Awareness Lights
L/UL Stations
d
-
-
Risk Assessment Example • Risk Assessment: Risk Reduction Measures Task
Hazard
RISK IN
PLr
1
A
1a
4
d
2
A
1b
1
3
B
1a
4
B
5
Risk Reduction Measures:
Severity
Exp osure
Avoida nce
Occurr ence
RISK OUT
Interlocked sliding door, Light curtain, Awareness light, Reduced robot speed controlled by Area scanner
S3
F1
A1
O1
1
b
Interlocked sliding door, Light curtain
S2
F1
A2
O1
0
1
b
Interlocked sliding door, Light curtain, Awareness light, Reduced robot speed controlled by Area scanner
S3
F1
A1
O1
1
1b
0
a
Interlocked sliding door, Light curtain
S2
F1
A1
O1
0
C
1a
3
c
Teach pendant (with enabling device and emergency stop), Manual reduced speed (T1)
S3
F1
A1
O1
1
6
C
1b
0
a
Teach pendant (with enabling device and emergency stop), Manual reduced speed (T1)
S2
F1
A1
O1
0
7
D
1a
3
c
Interlocked hinged door, Infeed light curtain, Interlocked sliding door, Emergency stop cable pull, Safe distance, Awareness signs
S3
F1
A1
O1
1
8
D
1b
0
a
Interlocked hinged door, Infeed light curtain, Interlocked sliding door, Safe distance, Awareness signs
S2
F1
A1
O1
0
9
D
2a
6
d
Interlocked hinged door, Infeed light curtain, Interlocked sliding door, Emergency stop cable pull, Safe distance, Awareness signs
S3
F1
A1
O1
1
10
D
2b
0
a
Interlocked hinged door, Infeed light curtain, Interlocked sliding door, Emergency stop cable pull, Safe distance, Awareness signs
S1
F1
A1
O1
0
11
D
2c
1
b
Interlocked hinged door, Infeed light curtain, Interlocked sliding door, Emergency stop cable pull, Safe distance, Awareness signs
S2
F1
A1
O1
0
12
D
3a
0
a
Interlocked hinged door, Infeed light curtain, Interlocked sliding door, Emergency stop cable pull, Safe distance, Awareness signs
S1
F1
A1
O1
0
13
E
1a
1
b
Control of hazardous energy (lockout/tagout), Safe work procedures
S1
F1
A1
O1
0
14
E
1b
0
a
Control of hazardous energy (lockout/tagout), Safe work procedures
S1
F1
A1
O1
0
15
E
2a
3
c
Control of hazardous energy (lockout/tagout), Safe work procedures
S1
F1
A1
O1
0
16
E
2b
0
a
Control of hazardous energy (lockout/tagout), Safe work procedures
S1
F1
A1
O1
0
17
E
2c
0
a
Control of hazardous energy (lockout/tagout), Safe work procedures
S1
F1
A1
O1
0
18
E
3a
0
a
Control of hazardous energy (lockout/tagout), Safe work procedures
S1
F1
A1
O1
0
ID
Technical Protective Measures & Administrative Measures
Review 1.
Process
The risk assessment process: • is used to reduce risks • is also used to more logically isolate / segregate various zones within complex automation systems
2.
Involvement of design engineers (systems, controls, etc.) in the risk assessment process is important in order to achieve maximum safety and productivity
3.
Other industrial safety standards can and should be used for additional guidance to maximize the results of a risk assessment
Risk
Productivity
Practical Benefit of Risk Assessment: Zone Determination by Layout Analysis
Mark Nehrkorn Director RCC Safety
SICK Inc. 6900 West 110th St. Minneapolis, MN USA Telephone: 952-941-6780 Email:
[email protected] www.sick.com/us/en/