Bridging the Gap: Bringing Operations and Maintenance into the Design Conversation

By Karen D. Morton, P.E.

Safety instrumented systems (SIS) are designed to protect people, processes, and facilities from hazardous events. Their success depends not only on how well they are engineered and installed, but also on how effectively they are maintained over time. Operations and maintenance (O&M) spans the longest and most variable phase of the safety lifecycle, yet it often receives limited consideration during the project design and execution phases.

The IEC 61511 standard, which governs SIS design and operation in the process industries, defines core responsibilities for maintaining long-term system performance. These include:

• Maintaining functional safety through consistent procedures and equipment tracking
• Periodically conducting proof tests based on Safety Integrity Level (SIL) verification
• Documenting test results, maintenance actions, and system changes
• Training personnel to ensure competency with SIS
• Applying a robust management of change (MOC) process
• Monitoring performance data to validate assumptions and guide improvements

Each of these elements are essential to sustaining the reliability of a safety system beyond startup. However, conditions in the field often complicate consistent implementation.

Practical Challenges in the Field

The demands placed on O&M teams frequently interfere with the ideal execution of these principles. One ongoing challenge is the steady loss of in-house experience. Industry-wide trends such as early retirements and workforce reductions have reduced the number of personnel with deep, site-specific knowledge. In many facilities, those remaining are expected to handle more responsibilities with fewer resources.

This environment increases the frequency of informal, undocumented workarounds. A technician responding to a process upset at night might reassign wiring or override a failed component to restore operations quickly. These emergency actions are often not recorded in the system documentation or reflected in updated drawings. As these changes accumulate, the disconnect between documented design and physical reality grows, making future troubleshooting more difficult and reducing system transparency.

Design decisions can also create operational complications. For instance, piping systems built to allow future expansion sometimes result in control valves that are oversized for the current flow volume. This can make it difficult to maintain stable control, requiring frequent valve retuning or workarounds that shift the burden from hardware to software.

Material compatibility presents another issue. Instruments may meet technical specifications but fail under actual process conditions. Some transmitters may be prone to fouling or plugging due to process buildup. Other components may perform poorly in the presence of extreme heat, humidity, or dust, especially in outdoor installations typical of Gulf Coast facilities.

Physical accessibility is a recurring obstacle. SIS components such as level transmitters or solenoid valves are sometimes installed in locations that are difficult or unsafe for maintenance personnel to reach without scaffolding or lift equipment. These placements delay testing and maintenance, increase exposure risk, and may reduce the frequency of preventive checks, particularly when staffing is limited.

In many cases, these issues are compounded by the lack of meaningful engagement between design teams and those who operate and maintain the system. An SIS must be integrated not only technically, but also operationally. Its effectiveness depends on how well it fits into established procedures, how clearly it is understood by the people using it, and how reliably it can be maintained over time.

How Engineering Teams Can Support O&M

Many of these challenges can be mitigated through earlier and more frequent collaboration between the design team and O&M personnel. Continuing that engagement throughout design and implementation can surface concerns that might otherwise go unaddressed.

Operations supervisors and maintenance technicians bring essential insights. They understand which device types have been reliable in their environment, where field conditions present limitations, and how specific equipment behaves under different seasonal or process conditions. They also know which installation approaches have created problems in the past, whether due to accessibility, interference, or serviceability.

Integrating that feedback into the design phase allows for adjustments that improve system reliability without increasing project cost. Selecting a different transmitter, relocating a component to eye level, or specifying a more accessible valve arrangement may seem like small decisions, but they can prevent years of recurring maintenance issues.

Design engineers can also improve project outcomes by streamlining communication across disciplines. Simplifying technical language, aligning expectations early, and reviewing relevant operating and testing procedures during design can help identify mismatches between design intent and operational reality.

Site visits offer another opportunity for productive exchange between the design engineers and O&M staff. These visits provide time to observe real-world constraints, ask specific questions, and gather feedback from personnel who work with the systems directly. A technician might point out an instrument that frequently fails in humid weather, or a junction box that requires a ladder to reach. Capturing those details and following up with the design team improves both the current project and future ones.

Designing for Long-Term Success

IEC 61511 is about both meeting regulatory requirements and emphasizing performance over time. The expectation is that safety systems will function effectively throughout their lifecycle. A design that looks complete on paper may fall short if it cannot be maintained, tested, or operated as intended in the field.

Supporting O&M begins with design, not with startup. Engineering decisions made during a project have long-lasting implications for system performance, operator safety, and plant reliability. When design teams collaborate early and consistently with operations and maintenance, the result is a safety system that meets standards and performs reliably in daily operation. For more information, contact our Team today.