Functional safety and alarm management in the process industry

In the Process Industry (Oil & Gas, oil refining, petrochemical, chemical, non-nuclear power generation, but also flammable deposits, oil & gas pipelines, distilleries, paper mills, pharmaceuticals, metals & mines and more generally all RIR industries) the risk for Life, Health and Environment of the production process concerns most industrial and semi-industrial installations.

The degree of risk of the production process is to be understood as a combination of the probability (low, moderate, high) of the potential incidental events that can be predicted and the level of the potential consequences (minor, serious, extensive, catastrophic).

An accidental event can generally result:

  • consequences for the life and health of production site personnel; and/or
  • consequences for the life and health of the community outside the production site; and/or
  • consequences for the Environment (air, soil, surface water, groundwater); and
  • direct and consequential material damages (equipment, machinery, structures, buildings, renovations, loss of production, loss of market share, penalties, fines, legal costs, damages)
  • intangible damages (loss of image due to association of the brand with the incident, negative media overexposure).

The increase in the degree of safety of the production process is a problem that involves social, regulatory, cultural, managerial, relational, productive, operational and maintenance aspects, management and control of Security, Quality and Security, as well as organisational, design, engineering and integrative aspects during the implementation phase.

Among the instrumented systems installed in most process industries, such as:

  • Process Control System;
  • Alarm System;
  • Security Instrumented System (SIS);
  • F&G system (F&GS);
  • Expert Information System;
  • Emergency Signalling and Alarm System.

In addition to the essential safety requirements of the European Seveso III and PED Directives in order to reduce the actual risk of major accidents, SIS and F&GS systems must comply with the requirements of the CEI EN 61508 and CEI EN 61511 standards.

In order to comply with the CEI EN 61508 Standard, and in particular for the Process Industry with the CEI EN 61511 Standard, for each Safety Instrumented System (SIS) and each Fire & Gas System (F&GS) deployed for the reduction of the risk for Safety and Environment, a Safety Life Cycle (supported by a functional safety management system) including the following activities must be foreseen:

  • Process Risk Analysis;
  • Allocation of safety functions and safety instrumented functions (SIF);
  • Determination of the target SIL of the SIF;
  • Elaboration of the Safety Requirements Specification (SRS);
  • Design, Engineering, HW and SW integration;
  • System verification (including verification of the actual SIL of the SIF);
  • FAT (Factory Acceptance Test);
  • Installation and Commissioning;
  • SAT (Site Acceptance Test);
  • Operation, Maintenance, Inspection and Testing.

The above activities will be planned and executed according to an Functional Safety Management System (FMS) compliant with the requirements of the applicable CEI EN 61508 and CEI EN 61511 standards.

As well as at least one Functional Safety Assessment (FSA), conducted by a functional safety expert, independent from the Project Team, should be performed before the installation is started or restarted, i.e. before potential hazards for Safety and Environment occur.

The effective reduction of risks for Safety and Environment, as well as for material damage, implemented through SIS and F&GS systems implemented and operated in compliance with CEI EN 61508 and CEI EN 61511 standards also brings benefits in terms of an improved assessment of the Manager’s Safety Index by the Authorities, as well as a reduction in insurance premiums.  The objectives of reducing the spurious failure rate of SIF sent by SRS are an important element in improving the operational reliability of the installation and reducing the risk associated with spurious failures.

The services that TECSA S.r.l. can render through its process security specialists, risk analysts and functional security experts in this field are:

  • definition and implementation of a Functional Security Management System Plan;
  • Process Risk Analysis (Hazid, HazOp, LOPA, up to a complete Quantitative Risk Assessment);
  • allocation of security functions (including alarms) and security instrumented functions (SIF);
  • determination of the SIL objective of the SIF;
  • development of the Security Requirements Specification (SRS);
  • verification of SIL and Spurious Failure Rate (STR) of SIF;
  • Functional Safety Assessment (FSA);
  • assessment of staff competence in the field of functional safety;
  • staff training courses on functional safety;
  • auditing activities of the functional safety management system and the functional safety plan.

This framework is completed by the services that Tecsa S.r.l. can provide to lay the foundations for the design of Alarm Management Systems according to ANSI/ISA 18-2 and EEMUA 191 standards.

To complete the consultancy on functional safety and management of alarm systems Tecsa S.r.l. through its certified technicians is able to provide specialized assistance in the field of functional safety and management of alarm systems:

  • basic and detailed engineering of supervisory and control systems (DCS, PLC) and safety (ESD);
  • basic and detailed engineering of gas and fire detection systems (F&G);
  • definition of the positioning criteria for F&G systems;
  • optimisation of the positioning of F&G systems (also through 3D simulation: “Fire&Gas Mapping”);
  • drawing up or checking the project time schedules for the automation part;
  • verification of P&IDs through comparison with process specifications (Cause Effects Matrix/Interlock Description) according to ISA regulations;
  • predisposition of cause-effect matrices;
  • checking the specifications of the safety interlocks;
  • definition of security critical alarms and blocks;
  • predisposition/verification of signal lists;
  • study and realization of architectures for the purchase of automation systems;
  • preparation/verification of technical specifications for automation for basic engineering, FEED, executive design;
  • specific preparation/verification for the purchase of systems;
  • verification and follow-up of supply specifications developed by vendors/contractors;
  • coordination and supervision of FAT phases of automation systems;
  • coordination of commissioning activities, loop checks, field tests for system acceptance (SAT).

Finally, it is useful to remember that Legislative Decree no. 105/2015, i.e. the Italian transposition of the Seveso III directive, provides that for safety block systems (typically ESD) the criteria for determining the construction, architectural and functional characteristics and periodic testing methods are indicated in the Plant Safety Report; this is also in relation to the risk analysis carried out and the identification of safety-critical elements.

Activities in the field of functional safety are conducted using special validated and internationally recognised software tools, including Exida’s exSILentia, which TECSA S.r.l., as Exida’s own channel partner for Italy, promotes.

TECSA S.r.l. boasts, inside:

  • 5 CFSP (Certified Functional Safety Professional) certified technicians;
  • 2 FGP certified technicians (Fire & Gas Professional);
  • 2 ALM (Alarm Management Professional) certified technicians;
  • 1 CSP (IACS Cybersecurity Professional) certified technician.

Luca Fiorentini, director and owner of TECSA S.r.l., has also worked as Principal Engineer for Exida LLC. itself since December 2019.