Services
Functional Safety and IACS Cybersecurity Services
Practical support for new projects, operating facilities and system modifications.
TVC helps organisations define requirements, review evidence and improve the practices supporting industrial safety and security. We agree the scope, responsibilities and deliverables for each assignment, from a focused technical review to coordinated lifecycle support.
IEC 61511
Functional Safety Services
Specialist support across the SIS safety lifecycle: management, safety requirements, design reviews, SIL verification, proof testing and Functional Safety Assessments.
Explore IEC 61511 services →IEC 62443
IACS Cybersecurity Services
Assess industrial cybersecurity risks and translate the findings into security requirements and practical improvement actions, including the interface with process safety.
Explore IEC 62443 services →Where the SIS sits
One hazard, several independent layers of protection
Risk reduction is shared between layers. Each one must be independent of the others and of the cause of the demand. The safety instrumented system is the layer IEC 61511 governs and the focus of TVC’s Functional Safety services.
Layer 4 of 7 · SIS · IEC 61511
Safety instrumented system
Sensors, logic solver and final elements that bring the process to a safe state on demand. Specified in the SRS, verified against its SIL, proof tested in operation.
IEC 61511 · Safety lifecycle
Support at every phase of the SIS safety lifecycle
From the first hazard study to decommissioning, each phase produces evidence the next one relies on. Select a phase to see the services that apply.
IEC 61511 · Management and analysis
IEC 61511 Functional Safety Services
Our services follow the SIS safety lifecycle. Management, planning, verification, assessment and documentation underpin the technical activities throughout the lifecycle.
01
Functional Safety Management and lifecycle planningEstablish the arrangements needed to manage Functional Safety consistently across your organisation or project.
- Develop or review Functional Safety Management procedures and project safety plans.
- Define competence requirements, responsibilities and supplier interfaces.
- Plan verification, validation, assessments and document control.
Typical deliverables: Management procedures, safety plans, responsibility matrices and gap reports.
02
Hazard and risk assessmentEstablish a sound basis for the required risk reduction and the role of the SIS.
- Support and review HAZOP and other hazard and risk assessment studies within the agreed scope.
- Review initiating events, consequences, risk criteria and protection assumptions.
- Track recommendations that affect the SIS and its safety requirements.
Typical deliverables: Study review findings, documented assumptions and action registers.
03
Allocation of safety functions to protection layersDefine the Safety Instrumented Functions and their required integrity.
- Support LOPA and SIL determination activities.
- Review protection-layer independence, dependencies and claimed risk reduction.
- Establish traceability between hazardous scenarios, allocated functions and SIL requirements.
Typical deliverables: SIF registers, SIL determination records and allocation review reports.
IEC 61511 · Engineering
Functional Safety engineering
04
Safety Requirements SpecificationTurn the risk assessment and allocation results into requirements that can be designed, verified and validated.
- Develop and review SRS documents and individual SIF specifications.
- Define trip conditions, safe states, operating modes and response requirements.
- Address bypasses, resets, fault response, interfaces and operational constraints.
- Specify maintenance, testing and application-program requirements.
Typical deliverables: SRS documents, SIF specification sheets and traceability reviews.
05
SIS design and application programmingReview the proposed solution and the evidence supporting its suitability for the application.
- Perform SIL verification and review failure data, architecture and common-cause assumptions.
- Review device selection, safety manuals and IEC 61511 prior-use evidence.
- Assess the complete final-element arrangement and its operating conditions.
- Review application-program specifications, design and verification records.
- Check proof-test coverage and intervals against the calculation assumptions.
Typical deliverables: SIL verification reports, device suitability reviews and design findings.
06
Factory acceptance testingPrepare for structured testing before delivery and installation.
- Review FAT plans, test procedures and acceptance criteria.
- Check coverage of SRS and application-program requirements.
- Review deviations, change control and completion evidence.
Typical deliverables: Reviewed FAT procedures, test findings and action registers.
07
Installation, commissioning and safety validationReview the evidence that the installed SIS meets its specified requirements.
- Review installation and commissioning records and SAT procedures.
- Develop or review validation plans with traceability to the SRS.
- Review complete SIF testing, interfaces and restoration of temporary test conditions.
- Assess deviations, handover records and operational readiness.
Typical deliverables: Validation plans, requirements-to-test matrices and completion review reports.
IEC 61511 · In operation
Functional Safety in operation
08
Operation, maintenance and proof testingPreserve the designed safety integrity throughout the operating life.
- Develop and review operating, maintenance and proof-test procedures.
- Review proof-test boundaries, acceptance criteria, coverage and intervals.
- Distinguish automatic diagnostics from proof tests intended to reveal hidden dangerous failures.
- Review partial-stroke and full-stroke tests, including realistic process conditions.
- Review bypass controls, compensating measures and return-to-service arrangements.
- Evaluate demands, failures, repairs and test records against design assumptions.
Typical deliverables: Proof-test procedures, performance reviews and improvement plans.
09
Modification and Management of Change (MOC)Determine how proposed changes affect existing safety functions and lifecycle evidence.
- Perform Functional Safety impact reviews.
- Identify risk assessment, SRS, design or calculation updates.
- Review verification, revalidation and assessment needs before authorisation.
Typical deliverables: Impact assessments, updated documentation and change review findings.
10
DecommissioningAddress the hazards and interfaces affected by withdrawing SIS protection.
- Review sequencing and remaining protection requirements.
- Identify temporary measures and authorisation arrangements.
- Review the evidence supporting safe withdrawal from service.
Typical deliverables: Decommissioning review reports and action lists.
11
Lifecycle verification and Functional Safety auditsVerification checks whether lifecycle outputs meet their specified inputs and requirements. Audits examine whether the required procedures and management arrangements are being followed.
- TVC supports both activities through document reviews, interviews and evidence-based findings.
IEC 61511 · Assessment
Functional Safety Assessments
A Functional Safety Assessment makes a judgement about the Functional Safety and safety integrity achieved by the SIS and its SIFs. TVC provides assessment support at agreed lifecycle milestones, taking account of previous findings and the work completed since earlier assessments.
Assessment planning defines scope, team competence, independence, required evidence and reporting arrangements. For Stages 1, 2 and 3, the team includes a senior competent person independent of the project design team. For Stages 4 and 5, the corresponding independence is from SIS operation and maintenance.
Typical deliverables: Assessment plans and reports, prioritised findings, recommendations and review of action closure.
Assessment stages
Stage 1
Safety requirements
Review after hazard and risk assessment, identification of required protection layers and development of the SRS. The assessment considers the risk-reduction basis, specification and management arrangements supporting the next activities.
Stage 2
SIS design
Review after SIS design. The assessment considers design evidence, verification results, device suitability and the treatment of outstanding requirements and findings.
Stage 3
Readiness before hazards are present
Review after installation, pre-commissioning and final SIS validation, with operation and maintenance procedures developed. The assessment addresses the evidence needed before process hazards are introduced.
Stage 4
Operating experience
Review after operating and maintenance experience has been gained. The assessment examines performance, failures, proof testing, maintenance and the continued validity of assumptions.
Stage 5
Modification and decommissioning
Review after modification and before decommissioning, as applicable. The assessment considers the affected safety functions and the relevant repeated or completed lifecycle activities.
IEC 62443-3-2 · Zones and conduits
Structure the system before you assess it
Assets with common security requirements are grouped into zones. Communication between zones is only allowed through defined conduits, each with its own boundary protection. The safety zone is kept separate from control and from the enterprise network.
IEC 62443 · Assessment
IACS Cybersecurity Services
Risk-based consultancy for industrial automation, control and safety systems. TVC supports asset owners and their engineering and service partners in applying the relevant parts of the IEC 62443 series. We consider the consequences of cyber events for people, the environment, production and system availability.
01
Security programme and gap assessmentEstablish governance and a prioritised improvement plan.
- Review policies, roles and procedures against applicable requirements.
- Support asset-owner security programme development using IEC 62443-2-1.
- Review access, supplier, change, incident and recovery management arrangements.
Typical deliverables: Gap reports, security programme procedures and improvement roadmaps.
02
System scope and initial risk assessmentDefine what needs protection and identify the significant risk scenarios.
- Define the system under consideration, boundaries and interfaces.
- Review assets, connectivity and existing protection measures.
- Use process hazard information to inform cyber-consequence evaluation.
Typical deliverables: Scope documents, asset inventory reviews and initial risk assessment records.
03
Zones, conduits and detailed risk assessmentStructure the assessment in accordance with IEC 62443-3-2.
- Define and review zones, conduits and trust boundaries.
- Assess threats, vulnerabilities and consequences for the agreed scope.
- Determine target security levels and risk-treatment requirements.
Typical deliverables: Zone-and-conduit documentation, detailed risk assessments and treatment plans.
04
Security requirements and design reviewTranslate assessment findings into requirements and evaluate proposed measures.
- Develop and review cybersecurity requirements specifications.
- Review segmentation, access controls, remote connections and system interfaces.
- Review requirements traceability and applicable IEC 62443-3-3 system requirements.
Typical deliverables: Requirements specifications, design findings and verification matrices.
IEC 62443 · Delivery and operation
Cybersecurity delivery and operation
05
Implementation verification and handoverReview whether specified security measures have been implemented and evidenced.
- Review configuration and acceptance documentation.
- Support security verification planning and evidence reviews.
- Define handover information and service-provider responsibilities, considering IEC 62443-2-4 where applicable.
Typical deliverables: Verification plans, evidence review reports and handover action lists.
06
Secure operation, maintenance and changeMaintain the security programme as systems and threats change.
- Review patch and vulnerability management procedures.
- Develop access, remote maintenance and removable-media controls.
- Review backups, recovery testing and incident response arrangements.
- Assess security impacts of proposed system changes.
- Support periodic reassessment and role-specific workshops.
Typical deliverables: Operating procedures, change reviews and improvement recommendations.
07
Cybersecurity for Safety Instrumented SystemsConnect industrial cybersecurity with Functional Safety responsibilities.
- Support SIS security risk assessments addressing IEC 61511 requirements.
- Review connected systems and interfaces that could affect SIF performance.
- Assess security measures for potential effects on safety and availability.
- Coordinate safety and security requirements through design and operational changes.
Typical deliverables: SIS security risk assessment reports, interface reviews and requirements.
A scope matched to your organisation
We agree the relevant standards, roles, assessment boundaries and deliverables at the start of each assignment. Recommendations account for legacy equipment, operational constraints and the need to maintain essential protection during implementation.
Discuss your IACS Cybersecurity requirementsTraining that supports implementation
Focused workshops and TÜV Rheinland programme courses can complement consultancy, helping your team understand the decisions, procedures and responsibilities needed to sustain the improvements.