CSA Z767 stipulates that human factors must be considered in risk identification and quantification. In doing so, the design of operator process/equipment interfaces with written guidelines and procedures, staffing levels, and the working environment (noise, vibration, lighting, temperature) should all be considered from the perspective of their effect on both the levels of protection (line of defense) against hazard occurrence provided by operators and the possibility that their actions might initiate hazard occurrence. Errors of both commission and omission need to be considered. The operator will contribute to one or more lines of defense (one or more layers of protection).
ELEMENT 7 – HUMAN FACTORS
A. INTRODUCTION
Human beings play a major role in all aspects of the design, construction, operation, and maintenance of a facility.
During each of these phases, human errors will occur and must be addressed.
“Human factors” is the term given to a wide range of human activity; however, the ultimate goal of human factors studies is to manage human error so the risk to people, property and the environment remains acceptable.
B. REQUIRED ELEMENTS
Operator-process/equipment interface
1. Each company/business/facility shall have a system in place to address human factors at the design, construction and operational phases of a project.
2. Each business/facility shall assess human interactions with the facility as part of the design process.
3. Human factors assessment shall address computerized control systems that can confront operators with unmanageable amounts of information during an upset condition (alarm management).
4. The human factors assessment system shall examine the following interfaces for potential problems:
a) Alarm display;
b) Information display; and
c) Ergonomics.
5. Each facility shall conduct task analyses to determine what can go wrong during a task, how it can be reversed through human recovery and, failing that, how the potential problem areas can be controlled.
Administrative control versus engineering control
6. Each business/facility shall have a strategy with respect to the use of administrative versus engineering controls.
Human error assessment
7. Each facility shall assess the potential for human errors throughout the facility lifecycle including design, construction, commissioning, operation and maintenance.
8. Each business/facility shall have access to competent resources for human error assessment.
9. Human factor reviews shall consider approaches to reducing human error that include:
a) Written guidelines and procedures;
b) Human factor audits;
c) Written communications; and
d) Design of operator-process/equipment interface.
C. RECOMMENDED GUIDELINES
Operator-process/equipment interface
1. Human factors assessment should address confusing equipment, positioning of dials, color coding, different directions for on/off, cultural norms, labeling, etc.
Administrative control versus engineering control
2. When administrative controls are implemented in preference to engineering controls, the facility should have a system to review the effectiveness of the administrative controls at a future date to ensure they remain effective.
Human error assessment
3. Human error reviews shall include factors such as understanding, judgment, motivation, education, training, stress, fatigue, and cognition.