1,721,349 research outputs found
Changes in IEC 61511 2nd Edition
Get PDFPresentationThe ISA (International Society of Automation) 84 standard (���Application of Safety Instrumented Systems for the Process Industries���) was first released in 1996. During the time of the development of ISA 84, the IEC (International Electrotechnical Commission) was working on the 61511 standard (���Functional Safety: Safety Instrumented Systems for the Process Industry Sector���). IEC 61511 was first released in 2003. ISA adopted the 61511 standard, with one additional clause, as ISA 84-2004. The IEC released a second edition of 61511 in 2016, followed shortly thereafter with a corrigendum (list of corrections) and an amendment that were finalized in 2017. The ISA 84 committee voted to accept the revised standard without modifications, and released it in mid-2018 as ISA 61511-2018. This presentation will summarize the changes in the new standard
Evolutionary Themes from ISA 84 to ISA 61511
Get PDFPresentationANSI/ISA 84.00.01 was the second edition of ISA standard to address safety instrumented systems for the process industry sector and was recognized by OSHA as a good engineering practice within process safety management. Nevertheless, standards must evolve over time based on application experience. After a decade of international process sector experience in applying these requirements for safety instrumented systems (SIS), a new edition of the IEC 61511 international standard was published. Recently published, ANSI/ISA 61511-1 brings the ISA standard into complete alignment with IEC 61511-1. This paper will review ten major themes of change between ANSI/ISA 84.00.01 and ANSI/ISA 61511-1
IEC 61511—functional safety in the process industry: the prominence of validation and verification in the lifecycle of a safety instrumented system
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As the concept of risk management has gathered momentum in the oil and gas industry during the past decade, so to has the adoption of IEC 61511, the internationally recognised standard for functional safety in the process industry. IEC 61511 is a risk-based standard that uses the concept of an electrical/electronic/programmable electronic based control system to implement autonomous means of risk reduction against a pre-defined unwanted hazardous deviation in a process.
While IEC 61511 has been in existence for more than a decade, the correct understanding and implementation of the standard to derive an effective demonstrate of compliance is still debatable.
The standard follows a cradle-to-grave approach to the lifecycle of any safety instrumented system and, unlike other standards where cherry-picking of the requirements may be carried out, IEC 61511 necessitates a demonstration of compliance to all lifecycle phases and their associated requirements.
The author of this peer-reviewed paper is fully aware of how difficult-to-digest the subject is; therefore, this paper on the prominence of validation and verification is presented in a pictorial, unambiguous and easy-to-digest manner while paying particular attention to the requirements defined for validation and verification in the standard. The topic of validation and verification in the overall lifecycle of IEC 61511 will be covered by the following questions:
What is the difference between validation and verification in the context of IEC 61511?
What is the difference between verification against IEC 61511 and IEC 61508?
When should planning for validation and verification happen?
When should validation and verification be carried out?
What are the implications of not carrying out validation and verification?
How does validation and verification fit into the wider context of the IEC 61511 lifecycle?
What level of independence is required for validation and verification?
The paper will also attempt to provide a practical example of how to implement an effective validation and verification strategy into an overall Functional Safety Plan to give the reader a clearer understanding of the obligations toward demonstrating compliance.</jats:p
Uncertainties in reliability calculations according to iec 61508 & 61511 standards
Get PDFLes normes de sécurité fonctionnelle IEC 61508 et IEC 61511 requièrent de prendre en compte les incertitudes relatives aux données de fiabilité pour les mesures probabilistes concernant les systèmes instrumentés de sécurité et proposent deux méthodes pour ce faire: utilisation des bornes supérieures à 70% ou des distributions complètes des paramètres de calcul. Dans la présente communication, les deux méthodes sont appliquées à trois cas d’étude : un système série, un système parallèle et un cas industriel. Pour cela, la suite logicielle GRIF (© Total S.A.) a été utilisée afin d’évaluer la probabilité moyenne de défaillance dangereuse en cas de sollicitation (PFDavg). Les calculs montrent qu’une des méthodes est plus pessimiste que l’autre lorsque l’incertitude sur les données de fiabilité est grande.Functional safety standards IEC 61508 and IEC 61511 require to take into account data uncertainties for probabilistic measures related to safety instrumented system and propose two approaches for doing that: use of the 70% upper bound or the full distribution of calculation parameters. In this paper, the two methods are applied to three application cases: a system in series, a system in parallel and a typical business case. The software GRIF (© Total S.A.) has been used in order to evaluate the mean probability of failure on demand (PFDavg). The results indicate that a method is more pessimistic when the reliability data uncertainty is great
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Addressing the Security Requirements in Functional Safety Standard IEC 61511-1:2016
Get PDFPresentationThe 2016 edition of IEC 61511-1: 2016 added two new requirements regarding the security of safety instrumented systems (SIS). The first requirement states that ���a security risk assessment shall be carried out to identify the security vulnerabilities of the SIS��� and the second requirement states that ���the design of the SIS shall be such that it provides the necessary resilience against the identified security risks���. The standard directs the reader to ISA TR84.00.09, ISO/IEC 27001:2013, and IEC 62443-2-1:2010 for further guidance on how to comply with these requirements. While these documents are informative, the 479 combined pages do not provide concise guidance on how to address the specific security requirements. The purpose of this paper is to offer step-by-step guidance on how to address the security requirements in 61511 and to identify specific clauses in the reference standards for further information
Refinery unit Basic Process Control and Safety Instrumented System Design Engineering Following IEC 61511 Standard
No full textU radu je opisan princip rada postrojenja za krekiranje vakuum plinskog ulja pomoću vodika, tzv. Hydrocracker postrojenja. Opisana je industrijska praksa i standardi vezani uz sustave upravljanja i sigurnosne instrumentacijske sustave s naglaskom na normu IEC 61511. Objašnjeni su koraci u projektiranju procesnih postrojenja te je opisana projektna dokumentacija i konfiguracija sustava upravljanja i sigurnosnog instrumentacijskog sustava. Za odabranu sigurnosnu instrumentacijsku funkcije je priložena relevantna projektna dokumentacija: prikaz na P&I dijagramu, specifikacija zahtjeva na SIF, matrica uzroka i posljedica, specifikacija instrumenata, SIL verifikacija.This thesis describes the principle of Hydrocracker plant operation. Industrial practice and standards related to control systems and safety instrumented systems are described, with emphasis on IEC 61511. Steps in process plant design, the project documentation and configuration of the basic process control system and safety instrumented system are explained. For the selected safety instrumented function, the relevant project documentation is enclosed: P&I diagram, safety requirement specification, cause and effect matrix, instrument specification, SIL verification
Dynamic Risk Analysis from the Perspective of Life Cycle Approach in Iec 61508 and Iec 61511
Get PDFDynamic risk analysis (DRA) aims to provide updated risk levels during operations of a hazardous facility. One of the main objectives of performing a DRA is to support day-to-day operational decisions, primarily for preventing major accidents. For this reason, many DRA methods have been developed to include information about the status of the safety barriers whose failures can increase the likelihood of a major accident. However, DRA is not widely used in industry, and there is no standard that describes DRA approaches and their applications. It may therefore be of interest to consider similar concepts and methods addressed in the existing standards. This paper focuses on a specific type of safety barriers, safety instrumented systems (SISs), and recognized functional standards IEC 61508 and IEC 61511 that give performance requirements to a SIS. In particular, SIS performance monitoring in the operational phase according to IEC 61508/61511 can provide valuable inputs to DRA applications.publishedVersio
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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