by Keith Brumbaugh , P.E., CFSE ​ Achieving Safety Integrity Level (SIL) targets can be difficult when proof test intervals approach turnaround intervals of five years or more. However, some process units have planned and predictable unplanned shutdowns multiple times a year. During these shutdowns, it may be possible to document that the safety devices functioned properly. This can be incorporated into SIL verification calculations to show that performance targets can now be met without incorporating expensive fault tolerance , online testing schemes, etc. This can result in considerable cost savings for an operating unit. The problem If a process plant is following the ANSI/ ISA 84.00.0 1 process safety lifecycle (i.e. ISA 84) or similar, as part of the allocation of safety functions to protection layers phase, a SIL assessment (e.g., a Layers of Protection Analysis (LOPA)) would be undertaken to assign Safety Integrity Levels (SIL) targets to a Safety Instrumented Function (SIF) . A scenario could occur in the design and engineering phase of the ISA 84 safety lifecycle when performing the SIL verification calculations, that the team discovers the SIFs do not meet their performance target. Assuming the calculation was done properly using valid data and assumptions, something would need to change in order to meet or exceed the required performance targets. This issue could occur in a Greenfield plant when first designing a SIF, but is more likely to be discovered during a revalidation cycle of a brownfield plant. Click here to view the complete whitepaper

Updated April 2026 - Written by aeSolutions Technical Team - There are many critical activities and decisions that take place prior to and during the Safety Integrity Level (SIL) Verification and other Conceptual Design phases of projects conforming to ISA84 & ISA/IEC 61511. These activities and decisions introduce either opportunities to optimize, or obstacles that impede project flow, depending when and how these decisions are managed. Implementing Safety Instrumented System (SIS) projects that support the long‐term viability of the Process Safety Lifecycle requires that SIS Engineering is in itself an engineering discipline that receives from, and feeds to, other engineering disciplines. This paper will examine lessons learned within the SIS Engineering discipline and between engineering disciplines that help or hinder SIS project execution in achieving the long‐term viability of the Safety Lifecycle. Avoiding these pitfalls can allow your projects to achieve the intended risk reduction and conformance to the ISA/IEC 61511 Safety Lifecycle, while avoiding the costs and delays of late‐stage design changes. Alternate execution strategies will be explored, as well as the risks of moving forward when limited information is available. Click here to view the complete whitepaper Topics Include: IEC 61511, ISA/IEC 61511 , Safety Instrumented Systems (SIS) , Independent Protection Layers (IPL) , Functional Safety Assessment (FSA) , Safety Requirement Specification (SRS) , Safety Lifecycle , Functional Safety Management Plan (FSMP ), Project Execution Plan (PEP), SIS Front‐End Loading (SIS FEL), Layer of Protection Analysis (LOPA ), SIL Verification ​

Updated April 2026 - Written by aeSolutions Technical Team - Some companies implement intermediate tasks during the analysis and design stages of an IEC/ISA 61511 Lifecycle Project with names such as “IPL Select” or “ LOPA Reconciliation”. The result of such studies is often a “refinement” of the control and/or safety system. Examples have ranged from identifying additional final elements to avoid the hazard, eliminating the use of shared instrumentation between protection layers, addressing response time issues, and assessing control system protection layers for full independence of a function against the initiating event and other protection layers. The benefit of such studies is that it’s easier and less expensive to make necessary changes to systems while the design is still on paper. It’s very expensive, and in some cases not even possible, to make design changes after systems have been installed. In the end, it all boils down to people. It is imperative that all personnel be competent in their roles within the Safety lifecycle. New people entering the industry need an opportunity to learn. Yet they need training, mentoring and reviews of their work in order to prevent systematic failures from creeping in and causing accidents. To read more examples of systematic failures throughout the lifecycle , and to learn how to reduce them, read the full paper “Methodologies in Reducing Systematic Failures of Wired IPLs” . Process Safety & Risk Management Industrial Safety Instrumented Systems

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Speak With One of Our Experts Today About Your Facility's Resilience — If It’s Critical, We Have it Covered — At aeSolutions we help clients reduce project chaos and strengthen performance by integrating the safety lifecycle with the full project lifecycle, and our PMO professionals ensure structure, accountability, and measurable progress. We work with your team to close gaps, clarify responsibilities, and convert fragmented practices into a unified approach that protects people, assets, and uptime. We help you move from risk to resilience with clarity and confidence. — Trusted By Industry Leaders — Ag Chem Battery Materials & Mineral Processing Chemical Manufacturing Energy & Power Generation Hydrogen Production & Processing Metals & Mining Processing Oil & Gas Production & Processing Petrochemicals & Hydrocarbon Processing Pharmaceutical & Life Sciences Manufacturing Renewable Fuels & Bioenergy Specialty Chemicals & Advanced Materials Utilities & Critical Infrastructure Ag Chem Battery Materials & Mineral Processing Chemical Manufacturing Energy & Power Generation Hydrogen Production & Processing Metals & Mining Processing Oil & Gas Production & Processing Petrochemicals & Hydrocarbon Processing Pharmaceutical & Life Sciences Manufacturing Renewable Fuels & Bioenergy Specialty Chemicals & Advanced Materials Utilities & Critical Infrastructure Ag Chem Battery Materials & Mineral Processing Chemical Manufacturing Energy & Power Generation Hydrogen Production & Processing Metals & Mining Processing Oil & Gas Production & Processing Petrochemicals & Hydrocarbon Processing Pharmaceutical & Life Sciences Manufacturing Renewable Fuels & Bioenergy Specialty Chemicals & Advanced Materials Utilities & Critical Infrastructure Click Here to Chat With Our Industry Experts — DON'T JUST TAKE OUR WORD FOR IT — Evidence-Backed Results Heater Controls Upgrade Improves Safety and Resilience of Arctic Pipeline Pump Stations Custom SI-BMS Solution Enhances Reliability and Safety for Critical Pipeline Transportation Facility Achieving a High-Risk Systems Overhaul on an Accelerated Schedule Multi-Fuel Boiler BMS Upgrade for Chlor Alkali Production Facility Chemical Facility FEL3 & Detail Design Achieves PSM OSHA Compliance Under Total Installed Cost Budget | A Masterclass In aeSolutions’ Lifecycle Solutions Capabilities Designing and Implementing a Fire & Gas Detection System for a Hydrogen Production Plant A Strategic Integration of SIS, BMS, and PSM in a Boiler Fuel Conversion Project Alarm Management for a Greenfield LNG Facility Pharma Company Detecting Natural Gas Leaks in Boiler House Large Specialty Chemical Company Reduces Alarm Floods Simplified, Cost-Effective, and Consistent Acidic Compound Detection Energy Company Reduces Regulatory Compliance Costs Saving Almost $50 Million Water Cannons Protect Community from Anhydrous Ammonia Leaks Pharmaceutical Company Required Toxic & Combustible Gas Detection System Complex Hot Cutover of Large Natural Gas Processing Facilities Specialty Chemical Site’s Increasingly Complicated Cutover “Fit for Purpose” Solution Reduces Planned Downtime by 66% Protecting Personnel with Practical Gas Detector Placement Alarm System Rationalization and Safe Operating Limit for Energy Production Heater Controls Upgrade Improves Safety and Resilience of Arctic Pipeline Pump Stations Custom SI-BMS Solution Enhances Reliability and Safety for Critical Pipeline Transportation Facility Achieving a High-Risk Systems Overhaul on an Accelerated Schedule Multi-Fuel Boiler BMS Upgrade for Chlor Alkali Production Facility Chemical Facility FEL3 & Detail Design Achieves PSM OSHA Compliance Under Total Installed Cost Budget | A Masterclass In aeSolutions’ Lifecycle Solutions Capabilities Designing and Implementing a Fire & Gas Detection System for a Hydrogen Production Plant A Strategic Integration of SIS, BMS, and PSM in a Boiler Fuel Conversion Project Alarm Management for a Greenfield LNG Facility Pharma Company Detecting Natural Gas Leaks in Boiler House Large Specialty Chemical Company Reduces Alarm Floods Simplified, Cost-Effective, and Consistent Acidic Compound Detection Energy Company Reduces Regulatory Compliance Costs Saving Almost $50 Million Water Cannons Protect Community from Anhydrous Ammonia Leaks Pharmaceutical Company Required Toxic & Combustible Gas Detection System Complex Hot Cutover of Large Natural Gas Processing Facilities Specialty Chemical Site’s Increasingly Complicated Cutover “Fit for Purpose” Solution Reduces Planned Downtime by 66% Protecting Personnel with Practical Gas Detector Placement Alarm System Rationalization and Safe Operating Limit for Energy Production View More Case Studies Here — News & Resources — The PHA Recommendation Playbook | Part 3 | Managing Scheduling and Operational Disruptions Whitepaper: Achieving 84-92% Urgent Alarm Reduction Through Comprehensive Lifecycle Implementation: A Dual-Unit Midstream Case Study Scoping Your Industrial Project: Best Practices for Success Control System Migrations | Part 7 | Best Practices for Installation, Testing, & Commissioning The PHA Recommendation Playbook | Part 2 | Untangling Technical Complexity The PHA Recommendation Playbook | Part 1 | Managing Resource Constraints — Let's Discuss Your Facility's Needs —

aeSolutions delivers SIL verification services to move your industrial manufacturing facility from Risk to Resilience and IEC 61511 compliance. SIL Verification Services Click Here to Chat With Our SIL Verification Experts Ensuring Safety Instrumented Functions Meet Required Performance and Risk Reduction Targets aeSolutions provides comprehensive SIL Verification services to confirm that Safety Instrumented Functions (SIFs) are designed to meet their required Safety Integrity Level (SIL) and deliver the intended risk reduction. Our structured, lifecycle-based approach evaluates whether your Safety Requirements Specification (SRS) aligns with the Safety Instrumented System (SIS) design and complies with applicable standards such as IEC 61511. Our SIL Verification Capabilities Include: Verification of Safety Instrumented Functions (SIFs) against required SIL targets Probability of Failure calculations and modeling Review of system architecture, redundancy, and fault tolerance Evaluating suitability of instrumentation, logic solvers, and final elements for use in SIS Common cause failure (CCF) assessment and mitigation strategies Verification of proof test intervals and maintenance assumptions Assessment of diagnostic coverage Gap analysis between design and Safety Requirements Specification (SRS) Documentation of verification results and compliance with IEC 61511 aeSolutions works closely with your engineering, operations, and safety teams to validate design assumptions, identify gaps early, and support informed decision-making. Whether supporting new projects or evaluating existing systems, our SIL Verification expertise helps ensure your safety systems are reliable, and compliant. — DON'T JUST TAKE OUR WORD FOR IT — Evidence-Backed Results — Trusted By Industry Leaders — Ag Chem Battery Materials & Mineral Processing Chemical Manufacturing Energy & Power Generation Hydrogen Production & Processing Metals & Mining Processing Oil & Gas Production & Processing Petrochemicals & Hydrocarbon Processing Pharmaceutical & Life Sciences Manufacturing Renewable Fuels & Bioenergy Specialty Chemicals & Advanced Materials Utilities & Critical Infrastructure Ag Chem Battery Materials & Mineral Processing Chemical Manufacturing Energy & Power Generation Hydrogen Production & Processing Metals & Mining Processing Oil & Gas Production & Processing Petrochemicals & Hydrocarbon Processing Pharmaceutical & Life Sciences Manufacturing Renewable Fuels & Bioenergy Specialty Chemicals & Advanced Materials Utilities & Critical Infrastructure Ag Chem Battery Materials & Mineral Processing Chemical Manufacturing Energy & Power Generation Hydrogen Production & Processing Metals & Mining Processing Oil & Gas Production & Processing Petrochemicals & Hydrocarbon Processing Pharmaceutical & Life Sciences Manufacturing Renewable Fuels & Bioenergy Specialty Chemicals & Advanced Materials Utilities & Critical Infrastructure Learn More About aeSolutions — Let's Discuss Your SIL Verification Needs —

aeSolutions Functional Safety Management services support moving industrial manufacturing facilities from Risk to Resilience by strengthening SIS lifecycle management and ensuring IEC 61511 compliance. Functional Safety Management Service Click Here to Chat With Our Functional Safety Management Experts Establishing and Sustaining Effective Functional Safety Programs Across the SIS Lifecycle aeSolutions provides Functional Safety Management (FSM) services to help facilities establish, implement, and sustain structured functional safety programs aligned with IEC 61511. Our lifecycle-based approach ensures that roles, responsibilities, procedures, and documentation are clearly defined and consistently executed across all phases of the Safety Instrumented System (SIS) lifecycle. Our Functional Safety Management Capabilities Include: Development and implementation of Functional Safety Management Plans (FMSP) aligned with IEC 61511 Definition of roles, responsibilities, and competency requirements for functional safety personnel Creation and standardization of procedures, work processes, and lifecycle documentation Integration of functional safety into management of change (MOC) processes Establishment of documentation, recordkeeping, and audit-ready practices Support for competency development, training, and qualification programs Gap assessments and benchmarking against industry standards and best practices Ongoing support to sustain and improve functional safety program performance aeSolutions works closely with your engineering, operations, and safety teams to implement practical, sustainable functional safety processes that align with how your facility operates. Whether building a new program or strengthening an existing one, our FSM expertise helps ensure your functional safety activities are consistent, compliant, and aligned with your facility's capabilities. — DON'T JUST TAKE OUR WORD FOR IT — Evidence-Backed Results — Trusted By Industry Leaders — Ag Chem Battery Materials & Mineral Processing Chemical Manufacturing Energy & Power Generation Hydrogen Production & Processing Metals & Mining Processing Oil & Gas Production & Processing Petrochemicals & Hydrocarbon Processing Pharmaceutical & Life Sciences Manufacturing Renewable Fuels & Bioenergy Specialty Chemicals & Advanced Materials Utilities & Critical Infrastructure Ag Chem Battery Materials & Mineral Processing Chemical Manufacturing Energy & Power Generation Hydrogen Production & Processing Metals & Mining Processing Oil & Gas Production & Processing Petrochemicals & Hydrocarbon Processing Pharmaceutical & Life Sciences Manufacturing Renewable Fuels & Bioenergy Specialty Chemicals & Advanced Materials Utilities & Critical Infrastructure Ag Chem Battery Materials & Mineral Processing Chemical Manufacturing Energy & Power Generation Hydrogen Production & Processing Metals & Mining Processing Oil & Gas Production & Processing Petrochemicals & Hydrocarbon Processing Pharmaceutical & Life Sciences Manufacturing Renewable Fuels & Bioenergy Specialty Chemicals & Advanced Materials Utilities & Critical Infrastructure Learn More About aeSolutions — Let's Discuss Your Functional Safety Management Needs —