Ensuring competency in functional safety is a crucial aspect of compliance with IEC 61511, a globally recognized standard for the safety instrumented systems (SIS) used in process industries. The standard outlines competency requirements for individuals involved in various lifecycle phases of SIS design, operation, and maintenance. These requirements encompass qualifications, experience, background knowledge, and specific expertise. By defining and documenting competency criteria, organizations can establish an audit trail to verify that systematic failure controls are effective.
A procedure shall be in place to manage competence of all those involved in the SIS life cycle. Periodic assessments shall be carried out to document the competence of individuals against the activities they are performing and on change of an individual within a role.
Defining Competency in IEC 61511
IEC 61511 does not impose rigid qualifications for all personnel involved in SIS projects. Instead, it emphasizes that each person must be competent for the specific tasks they perform. Competency is determined based on:
- Qualifications – Formal education and professional certifications in relevant engineering disciplines.
- General Experience – Broad industrial experience, particularly in process safety and risk management.
- Directly Relevant Experience – Hands-on experience with functional safety projects, SIS, and hazard analysis.
- Background Knowledge – Understanding of functional safety concepts, industry regulations, and best practices.
- Specific Knowledge – Familiarity with the processes, equipment, and operational procedures involved in SIS design and implementation.
The standard requires only that each person is competent for the tasks they are performing. It is not necessary for every engineer in the project to have a full in-depth knowledge of every aspect of the SIS. The standard does not make any specific stipulation about what competence actually means in practice: that is up to each individual organization to decide.
The Importance of Competency Assurance
Competency assurance in safety-critical industries is not just a regulatory requirement but a fundamental necessity for preventing catastrophic incidents. A lack of competency has been identified as a contributing factor in numerous industrial accidents. One notable example is the Aberfan Disaster of 1966, where a coal mine spoil heap collapsed, leading to 144 fatalities, including 116 children. The inquiry into the disaster found that mechanical engineers, rather than civil engineers, were responsible for managing the spoil heap, and they lacked the necessary expertise in geotechnical stability.
Similar competency-related failures have occurred in the process industries, reinforcing the need for organizations to ensure that personnel handling SIS tasks possess the requisite expertise.
Outsourcing and Competency Management
Modern industrial projects often involve multiple layers of outsourcing, making competency assurance more complex. Typically, an end-user delegates SIS-related activities to an Engineering, Procurement, and Construction (EPC) contractor, who may further engage:
- Manufacturers to supply SIS components.
- Consultants for safety analysis and verification.
- System integrators for programming and configuration.
Each transfer of responsibility increases the risk of competency gaps, making it essential for end-users to establish clear competency requirements and verification mechanisms. Without robust competency controls, there is no guarantee that outsourced safety solutions meet IEC 61511 compliance requirements.
Documenting the Competency
The following items shall be addressed and documented when considering the competence of persons, departments, organizations or other units involved in SIS safety life cycle activities.
- Engineering knowledge, training and experience appropriate to the process application.
- Engineering knowledge, training and experience appropriate to the applicable technology used (e.g., electrical, electronic or programmable electronic)
- Engineering knowledge, training and experience appropriate to the sensors and final elements.
- Safety engineering knowledge (e.g., process safety analysis)
- knowledge of the legal and regulatory functional safety requirements.
- adequate management and leadership skills appropriate to their role in the SIS safety lifecycle activities.
- Understanding of the potential consequence of an event.
- the Safey Integrity Level of (SIL) of the SIF (Safety Instrumented Function).
- The novelty and complexity of the application and the technology.
References:
- IEC 61511
- Functional Safety from Scratch by Peter Clarke xSeriCon
