Intro to TR15.306 and Task Based Risk Assessment
R. Todd DickeyEngineering Coordinator
Honda Engineering North America, Inc.
ANSI-Registered TR R15.306-2016
Task-based risk assessment– Updates the 2014 version of the
TR 306, which…• Updates the guidance given in
ANSI/RIA R15.06-1999, Clause 9
• Published in May 2016
– Key updates:• Table 2 – Risk level decision matrix
• Table 3 – Hierarchy of risk reduction measures
• Table 5 – Minimum functional safety performance
Representations of Risk
Risk can be conceptualized in a number of ways:
RISK
related
to the
considered
hazard
SEVERITY
OF HARM
that can result
from the
considered
hazard
is a
function
of
and
PROBABILITY OF
OCCURRENCE
of that harm
exposure to a
hazardous situation
the occurrence of a
hazardous event
the possibility to avoid
or limit the harm
Hazard
Risk
Exposure
Vulnerability
ISO/IEC Guide 51:2014(E)
Table 1
WHO Model used to describe natural
disasters
Risk Assessment (Part 2, 4.3)
• A systematic analysis of the tasks, hazards, and risksassociated with the robot system over its life cycle– Task (ISO 12100:2010, 3.25): specific activity performed by one or
more persons on, or in the vicinity of, the machine during its life cycle
– Hazard (ISO 12100:2010, 3.6): potential source of (physical injury or damage to health)
• ANSI/RIA R15.06-1999: Risk assessment was optional and a methodology was included in the standard
• ANSI/RIA R15.06-2012: Risk assessment is required but a methodology was not included in the standard
• RIA TR R15.306-2016: Risk assessment methodology that meets the requirements of R15.06-2012
Risk Assessment Process Flow
• Has been widely adopted for industrial automation since first appearence in ANSI/RIA R15.06-1999
• Any task-based risk assessment methodology is acceptable
ISO 12100:2010 Fig.1
Analysis of Initial Risk• New: 3x3x3 matrix• Initial risk is
assessed under the assumption no risk reduction measures have been implemented
• Requirements for risk reduction are a function of the severity, exposure and avoidance analysis
Risk Reduction and Safeguarding
• The hierarchy of risk reduction measures describes the preferred order for implementing risk reduction measures
Summary of Table 3 – Hierarchy of Risk Reduction Measures
Risk
Elimination
Substitution
Limit Interaction
Safeguards & SRP/CS
Complementary Protective
Measures
Warnings & Awareness
Means
Administrative Controls
Personal Protective
Equipment (PPE)
RIA TR R15.306-2016 Table 3
Risk Reduction and Safeguarding
The appropriate risk reduction measure is directly tied to the risk level
Functional Safety (SRP/CS)
Analysis of the hazard will establish the required performance level as described in ISO 13849-1
Summary• General guidance for task based risk assessment
process methodology can be found in ANSI B11.0 and ISO 12100
• TR R15.306 provides a methodology for industrial robot system applications
• Effective safeguarding utilizes several conjunctive risk reduction measures
• Risk reduction should adhere to the hierarchy for the most effective safeguarding
• Functional safety ensures that safety functions relying on a control system will be effective for the associated risk(s)
R. Todd Dickey
Engineering Coordinator
Honda Engineering North America, Inc.Marysville, Ohio USA
Telephone: +1 (937) 642-5000 Ext.61186
Contact Information