From safety silos to strategic insights: Phillips 66 digitally transforms SIS management

When it comes to digital transformation, refining and processing operators face unique challenges. Unlike other industries already leveraging digital twins to improve design, enable predictive maintenance and boost operational efficiency, the refining and processing sectors often struggle with data management.

Many facilities have accumulated vast quantities of data over decades, some dating back over half a century. This data is often scattered across departments, locked in outdated formats and managed by tools from different generations. Such fragmentation makes digital transformation complex, as updating one document can render others outdated, creating uncertainty about which version is accurate.

“Everyone is looking to digitalization, but in refining, it is not that simple,” says Nagappan Muthiah, P.E, CFSE – Phillips 66 Safety Instrumented Systems Lead, Industrial Control Systems.

Muthiah and his team at Phillips 66 were tasked with leading the digital transformation of the company’s Safety Instrumented Systems (SIS). Their mission: identify the best way to consolidate decades of dispersed and inconsistent safety data into a smarter, more practical system. This innovative solution aims to eliminate data silos, deliver enterprise-wide visibility and bring greater clarity to safety lifecycle management.

The reality of digitalization in refining

Phillips 66, headquartered in Houston, operates nine refineries and initially set out to pursue full lifecycle digitalization when it began its digital journey over five years ago. This would allow it to replicate its entire safety system digitally from front-end design through to commissioning. In theory, the process would deliver enormous savings in both time and money: design one unit, press a button and replicate it across sites.

“As much as it was intellectually satisfying to conceptualize the digitization of the entire process, including front-end design to operation and maintenance,” adds Muthiah. “We quickly realized that the ROI just wasn’t there.”

The true opportunity wasn’t in digitizing front-end design data but in focusing on operations, maintenance and safety performance data of the existing assets.

Phillips 66 made a strategic decision to reorient its digitalization efforts around SIS during the operations and maintenance (O&M) phase — where proactive decisions directly impact reliability, uptime and safety.

This approach aligned with guidance from the American Petroleum Institute’s (API) Recommended Practice 754, which classifies safety metrics into four tiers. While Tier 1 and Tier 2 reflect incidents that have already occurred, Tier 3 metrics act as leading indicators — revealing that a safety protection system was activated to prevent a potential event.

“Before we started utilizing SIL Solver Enterprise, our safety data lived in siloed digital formats,” explains Muthiah. “You could read it — but tracking, comparing or integrating this safety design basis was much harder.”

From documentation to real-time decision support

Phillips 66’s safety lifecycle tool, SIL Solver Enterprise, was developed by Dr. Angela Summers, a licensed professional engineer with over 30 years of experience in SIS and a key contributor to industry standards from ISA, IEC and others. Originally created to calculate the Probability of Failure on Demand (PFD) and Spurious Trip Rate (STR) for process facility equipment, the software has evolved into a fully integrated safety management platform. It supports the entire SIS process — from design and documentation to compliance and governance — enabling digital transformation, eliminating data silos and providing consistent visibility across the enterprise.

The secure, cloud-based architecture from SIS-TECH allowed Phillips 66 to centralize all SIS data across its refining assets. Rather than managing static reports in disconnected systems, teams now work within a dynamic environment where safety data can be filtered, analyzed and compared across units and facilities. Updates made in one area are automatically reflected across all related documentation, ensuring accuracy and alignment from field operations to corporate safety audits.

“It was a paradigm shift — going from exchanging documents to exchanging data,” says Muthiah. “Suddenly, we could slice, dice and act on our safety insights.”

SIL Solver enables Phillips 66 to compare SIL ratings across similar systems, standardize processes and ask deeper operational questions: Why does one refinery require more SIL 2 functions than another? Is the risk profile accurate, or are assumptions misaligned? What about this outlier data?

With their SIS data structured and centralized, Phillips 66 is now uncovering patterns that were previously hidden.

Strategic alignment with industry direction

The ongoing efforts to access, analyze and visualize SIS data in aggregate are helping Phillips 66 become increasingly proactive in its safety management. As this work progresses, their teams are beginning to identify systemic issues and risk clusters, moving beyond merely addressing isolated failures.

“When you zoom out and leverage relevant data, you move beyond addressing isolated issues and start resolving the root causes within the entire system,” adds Muthiah.

Phillips 66’s Safety Instrumented Systems digital transformation aligns with the Industry 4.0 Maturity Index developed by the National Academy of Science and Engineering (acatech) in Germany. The framework outlines six stages of digital maturity:

• Stage 1: Computerization – Digitization of analog systems.
• Stage 2: Connectivity – Systems and data connected across departments, enabling communication.
• Stage 3: Visibility – Real-time insights into what’s happening.
• Stage 4: Transparency – Root-cause analysis explains why things are happening.
• Stage 5: Predictability – Anticipating outcomes of future issues or performance.
• Stage 6: Adaptability – Autonomous response to changing conditions.

After several years of focused effort — and with the right tools now in place — Phillips 66 sees itself firmly in Stage 2 and advancing toward Stage 3. At that level, SIL Solver Enterprise will enable the comparison of “evergreen” static safety design data, which reflects how systems should operate, with real-time operational data from the field, to generate Tier 3 Metrics aligned with API-752. The next step, Stage 4, is where Muthiah believes real efficiencies will begin to emerge.

“We believe Stage 4 will be a sweet spot — where digitally mapped data helps us make decisions not just based on theoretical analysis, but on real-world analytics that further improve our safety and reliability,” adds Muthiah.

From data-driven safety to operational excellence

For Phillips 66, future goals include extending insights from SIS into Equipment Protection Systems (EPS), where greater digital transparency can enhance both safety and plant efficiency. As operational data continues to mature, the company expects to make even more impactful, real-time decisions.

“The next step would be to expand the applications to include asset protection and production loss,” concludes Muthiah. “If a piece of equipment is tripping, there’s a safety aspect — but also a commercial one. Your unit is down, you’re not making money. By looking at the metrics, we expect to improve uptime.”

Rather than attempting a sweeping overhaul, Phillips 66 took a targeted, outcome-driven approach to digital transformation. In doing so, the company transitioned from fragmented, document-heavy SIS management to a streamlined, data-centric platform. The results: greater efficiency, compliance validation and enterprise-wide visibility. Their journey offers a practical model for how legacy-heavy industries can evolve with clarity, purpose and measurable impact.

“We’re not trying to digitalize for digitalization’s sake,” explains Muthiah. “We’re focused on what improves safety and reliability — period.”