One team. One lifecycle. Safer systems by design.

Watchmen supports the development of comprehensive SIS Lifecycle Management Plans tailored to meet the requirements of IEC 61511 and the specific needs of your facility. Our plans define clear roles, responsibilities, procedures, and documentation expectations across all phases—from SIL determination and design through to operation, maintenance, and decommissioning. We ensure that your lifecycle framework promotes consistency, facilitates audits, and aligns with corporate risk policies, while also providing practical tools to manage proof testing, bypasses, overrides, and functional safety assessments. With Watchmen, you gain a structured, auditable foundation for maintaining SIS integrity throughout the life of your plant. 

SIL verification calculations are performed to verify a proposed design meets the safety integrity target identified in a SIL assessment.  Watchmen can perform these calculations quickly and accurately presenting options that can minimize the need for additional hardware or redundancy and maximizing proof test interval.  A strong understanding of this technique can often save money stemming from over designing.  Under designing can leave you lacking protection.

A comprehensive Safety Requirement Specification (SRS) is a key document used to ensure all SIF's are designed, installed, maintained and tested properly to ensure they provide the needed safety integrity.  Watchmen can provide detailed and comprehensive SRS packages quickly and effectively using our proprietary SRS tools.

 Watchmen supports the development of comprehensive Factory Acceptance Testing (FAT), Integrated FAT (IFAT), and Site Acceptance Testing (SAT) procedures tailored to your SIS design and project execution strategy. Our team ensures that each test procedure is traceable to the Safety Requirements Specification (SRS), covers all safety logic, I/O verification, alarms, interlocks, and manual actions, and reflects realistic field conditions where applicable. We also incorporate key validation steps to support Functional Safety Assessment (FSA) requirements. By aligning with IEC 61511 and integrating stakeholder feedback early, our testing procedures reduce commissioning risks, improve test efficiency, and help demonstrate that the installed SIS meets both design intent and functional safety objectives. 

Performing an effective proof test is critical to maximizing SIL performance and extending the test interval.  Watchmen can develop comprehensive test procedures that will maximize proof test coverage.  Our easy to use checklists and procedures will help you to document the regular testing being performed and take action if there are any failures.

 Watchmen provides independent and technically rigorous Functional Safety Assessment (FSA) services across all lifecycle stages in accordance with IEC 61511. Our assessors bring a detailed understanding of SIS design, implementation, and operations to evaluate whether functional safety requirements have been met and adequately documented. From early-phase assessments confirming the validity of hazard and risk analyses (FSA-1), to detailed reviews of design and implementation (FSA-2), through to final validation and operational readiness (FSA-3), and covering the operations and maintenance phase (FSA-4) and modifications (FSA-5), we help ensure that your SIS is compliant, defensible, and audit-ready. We also support gap assessments and action tracking to close findings efficiently and maintain ongoing system integrity. 

A Functional Safety Assessment (FSA) is a critical audit activity performed at defined stages of the SIS lifecycle to evaluate whether the Safety Instrumented System is capable of achieving the required Safety Integrity Level (SIL). There are many interdependent activities involved in implementing a compliant and effective SIS—and just as many opportunities for gaps or missteps. An FSA helps identify weaknesses in documentation, process execution, or system design before they impact safety or compliance. IEC 61511 mandates that these assessments be conducted by a competent and independent party—separate from those involved in SIS design, operation, or maintenance.

At Watchmen, we offer comprehensive FSA services at all stages (FSA-1 through FSA-4), combining technical rigor with practical insight. Our assessments include detailed reviews of engineering documents, plans, procedures, and test records, along with site inspections of installed Safety Instrumented Functions (SIFs) and interviews with key personnel. Throughout the process, we don’t just identify gaps—we also coach your team, sharing best practices and IEC 61511 interpretations to build in-house understanding and long-term functional safety capability. Whether supporting a greenfield startup or evaluating a legacy system, Watchmen’s FSA services deliver both compliance assurance and continuous improvement.

Regular SIS audits are necessary for compliance with IEC 61511 and are performed during the operating phase of the lifecycle to validate that a SIS Functional Safety Management System is in place, up to date and being followed.  Where gaps in the process are revealed by the audit, recommendations are provided to improve upon the process to ensure the SIS and associated SIF(s) provide the reliability intended.   The SIS Audit may be performed together with the Stage 4 FSA.   

Watchmen recommends that the SIS Audit be performed annually for the first few years of installation and then potentially extended out once it can be seen audits are no longer identifying gaps in the process.  Performing an audit within the first year following placing SIF(s) in service is very important, since this often reveals serious issues that may impair SIF integrity.