This integrative systems perspective is often missing or poorly emphasized in much of the risk management literature. It provides concise, yet comprehensive coverage of the key components of risk management as applied to the process and manufacturing industries.
3 System Models for Risk Management
4 Identifying Hazards and Operational Problems
5 Analysing the Consequences of Incidents
6 Effect Models for Consequence Analysis
7 Vulnerability Models
8 Estimating the Likelihood of Incidents
9 Risk Estimation
10 Decision Making under Uncertainty
11 Process Safety Management Systems
12 Life Cycle Risk Management Tools
13 Management of Major Hazard Facilities
14 Auditing Process Safety Management Systems
15 Land Use Planning Risk Management
MANAGING RISKS FROM PROCESS SYSTEMS
WHY RISK MANAGEMENT?
- Regulatory Requirements
- Common Law Duty of Care
- Commercial Reasons
- Evaluation of Alternative Options
The Royal Commission of Inquiry into the accident attributed one of the causes to the lack of a risk management process in place (Hopkins 2000). Particular emphasis is placed on systems approaches to process risk management within the framework of the process life cycle.
HAZARD AND RISK
- Hazard
- Risk
- Risk as an Ascribed Quantity
In the context of an industrial operation, these can be considered as hazards: i) The presence of high pressures or temperatures in the system (ii) The act of smoking in certain areas. iii) Explosive properties of a material (iv) Inappropriate behavior of personnel. v) Storage of large quantities of toxic substances. vi) Industrial operations near urban areas with high population density. The above examples illustrate that risk has two dimensions: .. the severity or magnitude of the loss event .. the likelihood or probability of occurrence.
THE NATURE AND ROLE OF RISK MANAGEMENT
- The Dimensions of Risk in Process Systems
- Project risks
- The Key Players in Risk Management
One of the major problem areas for an organization in managing environmental risk is the long-term impact. If an organization designs a bridge, and there are design flaws in the project that lead to a failure of the structure, a whole range of liabilities arises.
HAZARD AND RISK I N PROCESS SYSTEMS .1 The Incident Spectrum
- Events and Incidents in Process Systems
- Contributing Factors to Process Risk
- The Ubiquitous Nature of Uncertainty
However, as we discuss in Chapter 15, the issue of risk perception is critical to the overall effectiveness of risk management practice. In the context of this book, we specifically use the words "event," "incident," and "accident."
THE REGULATORY ENVIRONMENT OF RISK MANAGEMENT .1 International Conventions
- National and Local Regulatory Frameworks
Regulations in this area often overlap with occupational safety and health laws and environmental protection laws. In the area of control of major hazardous facilities, the National Occupational Health and Safety Commission has published a National Standard and Code of Practice (NOHSC, but it is advisory only.
Likewise, the popular view of risk, which includes a degree of outrage, is a very real phenomenon and needs to be addressed by governments and industry advocates. In summary, the concept of danger and risk can be expressed in a few simple words:
CFR 1910.119:1992
- NOTATION ADG
EC96 1997, Seveso II Directive (96/82/EC) on the control of major-accident hazards involving dangerous substances, Official Journal of the European Communities, L10/13-33. EC99 1999, Directive 1999/45/EC on the classification, packaging and labeling of dangerous preparations, Official Journal of the European Communities, L200/1-68.
RISK - ESTIMATION, PRESENTATION AND
MEASURES OF RISK
- Need for Risk Measurement
- Qualitative and Quantitative Measures
Qualitative analysis can be used early in the risk management process to classify those events or incidents that require further detailed consideration. The stage of the process or product life cycle at which risk management activities are performed will also determine the level of analysis possible and justified.
SOCIETAL RISK
INDIVIDUAL RISK
- Units of Risk
- Risk of Injury to People
- Risk of Fatality
- Corporate Reputation and Public Outrage Risk
In the case of quantitative risk analysis (QRA), risk assessment is the quantification of uncertainty. For the risk of death to workers, a commonly used index in manufacturing industries is the fatal accident rate (FAR).
RISK REPRESENTATION
- Spatially Distributed Risks
- Linear Risks
The outrage can be of such a level that, in the event of a major accident, government or local communities can directly influence corporate responsibility or planning. In this case, there is a sharp cut-off in the area with 100 fatalities, which illustrates a requirement for the facility's design. In these cases, risks extend along the length of the corridor and are reduced in the direction perpendicular to the corridor.
RISK TARGETS, TOLERABILITY AND ACCEPTABILITY .1 Tolerability and Acceptability of Risk
- Risk Target Setting
Other important aspects such as relevant stakeholders, risk bearers and tolerability play their role in the application of ALARP (HSE 1992; . Melchers, 2000; HSE, 2001). This follows a similar decision by the Health & Safety Executive in Great Britain (HSE 1990). Nevertheless, some criteria exist, especially in the Netherlands (Ale, 1991; Jonkman et al. 2003) and in Hong Kong.
RISK PERCEPTION
- The Importance of Risk Perception
- Factors Affecting Risk Perception
Regardless of the technical advice offered, people's perception of a risk can dominate the particular. In particular, the understanding of risk perception is strongly influenced by the local context, involving aspects such as (Walker et al. 1998): ii) first-hand experiences of accidents or emergencies on site (iii) sensory evidence such as things seen or smelled. iv) interpretation of company information issued to the public. Subsequent chapters will reinforce the influence of values and perception on key areas of risk management.
REVIEW
All these factors only reinforce the value-laden nature of risk management and emphasize the need to take these aspects seriously in risk management practice.
2001, 'Safety Weighted Hazard Index (SWeHI), A new user-friendly tool for rapid yet comprehensive hazard identification and safety assessment in chemical process industries', Transactions of the Institution of Chemical Engineers, vol. 1990, 'The social acceptability of the chemical and process industries: A proposal for an integrated approach', Transactions of the Institution of Chemical Engineers, vol. 1997, 'Risk analysis and risk perception: the social limits of technological change', Anniversary Lecture IChemE 1997, Transactions of the Institution of Chemical Engineers, Part B, vol.
NOTATION
SYSTEM MODELS FOR RISK MANAGEMENT
LIFE CYCLE RISK MANAGEMENT
There is some overlap of lifecycle components, but these two aspects of the lifecycle are fundamentally different. A detailed discussion of risk management through the life cycle of a facility is provided in Chapter 12. From a process systems perspective, the environmental life cycle for a process facility consists of the steps shown in Figure 3-2.
ONE AND TWO DIMENSIONAL MODELS OF RISK
- One-Dimensional Model
- Two-Dimensional Model
Selecting the appropriate tool or combination of tools is critical to the success of the hazard identification step. Details of the methods and recommended selection criteria for different situations are provided in Chapter 4. 34; We weigh the size of the risk and the cost of its reduction in money, time and trouble.
LAYERED PROTECTION MODELS
As in layer 2, this depends on the effective diagnosis, available response time and operator experience. By the time the standby pump was started, the skin temperature of the tubes in the furnace reached a failure level and the tube ruptured. How much credit can be given to the skill and dedication of the operators, remembering that the safety management system should be 'system dependent' and not 'individual dependent'.
RISK RANKING MODELS
A risk matrix is a graphical representation of risk as a function of probability (probability) and consequence (severity). The judgment of the participating team from the corporation is essential to the use of the risk matrix for the allocation and ranking of risks. Frequency descriptions should be prepared for each individual risk assessment so that the time range is appropriate for the level of detail of the risk assessment.
INTEGRATED SYSTEMS MODELS
- Integrating Safety, Environment and Quality
- Generalised Hazard System Model
Let us postulate that due to some fault in the maintenance equipment (R2), the gas finds an ignition source and a jet fire occurs. In the absence of appropriate software, the different stages of risk assessment must be carried out individually, and the advantage of 'integration' is lost. There have been continuous efforts in the industry to develop the integrated software, but these have not found universal acceptance due to their complexity and apparent lack of flexibility and transparency.
HIERARCHY OF MANAGING PROCESS RISK
Provides a good first-pass risk assessment for decision-making on issues such as facility location and land use planning. The software is essentially a "black box" over which there is very little control, especially for non-experts. Due to the lack of detailed information about the risk assessment process, the process is not transparent for verification and audit purposes.
REVIEW
This model is also related to Layer of Protection Analysis (LOPA), described further in Chapter 8. Difficulties in using this model and methods to overcome these difficulties are described in the discussion of risk assessment in Chapter 9. The hierarchical approach to Risk Management and links to layered protection models are described.
2003a, 'An overview of process fault detection and diagnosis Part 1: Quantitative model-based methods', Computers and Chemical Engineering, Vol. 2003b, 'An overview of process fault detection and diagnosis Part 2: Qualitative models and research strategies', Computers and Chemical Engineering, Vol. 2003c, 'An overview of process fault detection and diagnosis Part 3: Methods based on process history', Computers and Chemical Engineering, Vol.
NOTATION ALARP
1999, 'The Origins and History of Loss Prevention', Transactions of Institution of Chemical Engineers, Part B, Process Safety and Environmental Protection, vol. 2000, 'Determination of 'best available techniques' for integrated pollution prevention and control: a life cycle approach', Transactions of Institution of Chemical Engineers, Part B, Process Safety and Environmental Protection, vol. 2000, 'Sneak Analysis of Process Systems', Transactions of Institution of Chemical Engineers, Part B, Process Safety and Environmental Protection, Vol.
IDENTIFYING HAZARDS AND OPERATIONAL PROBLEMS
INTRODUCTION
Hazard identification for this level refers to the inherent hazard of the stored or processed material and the safeguards in place to prevent loss of containment. The above approach may not identify the root causes of process hazards, especially due to unusual situations and deviations from intended operation (Johnson 2000). This chapter is devoted to the systematic hazard identification techniques available for the detailed identification of process hazards and the suitability of each technique for different phases of the life cycle.
AN OVERVIEW OF HAZARD IDENTIFICATION .1 The Dimensions of Hazard Identification
- Approaches to Hazard Identification
- System Interactions and their Importance .1 Linear interactions
It is based entirely on the expertise of the risk identification team, with input from literature data on past experience. A separate boiler feed water (BFW) pump supplies the tubes to the furnace convection bank and the steam is separated into a steam boiler. All of the above issues should be addressed systematically using one or more of the hazard identification methods.
COMPARATIVE HAZARD IDENTIFICATION METHODS .1 Past Experience
- Incident Databases
- Analysis of Incident Statistics
- Checklists, Standards and Codes of Practice
- Process Hazard Identification Matrix
- What-If Analysis
- Semi-quantitative Methods
If more information is known about specific interactions, this can be used to populate the cells in the matrix. The Dow Fire and Explosion Index (F&EI) is based on the hazardous properties of the process unit material inventory and operating conditions. It can be used to classify chemical hazards in the initial stages of hazard assessment.
FUNDAMENTAL HAZARD IDENTIFICATION METHODS .1 Concept Hazard Analysis
- Failure Mode and Effects Analysis (FMEA)
- Hazard and Operability Study
- Identification of Chemical Reactivity Hazards
- Scenario Based Hazard Identification
- Documentation and Software Systems
Depending on the level of analysis, the whole hierarchy or a part of the hierarchy can be selected. FMEA often focuses more on failure modes than on the causes of failure modes. The computer term HAZOP or CHAZOP was given to the application of the HAZOP method to PES.
QUALITY AND COMPLETENESS OF STUDIES
- Comparison of Capabilities of Hazard Identification Models
- Socio-Technical Factors in Identification of Root Causes
- Hazard Identification for Facility Life Cycle
- Quality Control Procedures
- Uncertainty in Hazard Identification
An overview summary of the hazard identification models and their capabilities is given in Table 4-12. FMEA is extremely suitable for hazard identification of programmable electronic systems, where none of the other techniques are capable. This can be supplemented by a scenario-based hazard identification for identifying major hazards during commissioning.
Model Unit System', Transactions of the Institute of Chemical Engineers, Part B, Process Safety and Environmental Protection, Vol. Accidents that could happen in your plant', Process Safety Progress, vol. 2002, 'A joint analysis of process and operator performance in chemical process operational safety', Journal of Loss Prevention in the Process Industries, vol. Their identification and evaluation', Transactions of the Institution of Chemical Engineers, Part B, Process Safety and Environmental Protection, vol.
NOTATION
1994, 'A Toxicity Hazard Index' in Hazards XII, European Advances in Process Safety, IChemE Symposium Series, no. 2003, Risk and Reliability Management in Process Plants, Gulf Professional Publishing. ed) 1999, Bretherick Handbook of Reactive Chemical Hazards, 6n edn, Vols. 1994, 'Improvements in pre-HAZOP process safety reviews' in Hazards XII, European Advances in Process Safety, IChemE Symposium Series, no. Major Accident Hazards Office Major Accident Reporting System System Event Data for Major Hazards Material Safety Data Sheet.
ANALYSING THE CONSEQUENCES OF INCIDENTS
EVENTS, INCIDENTS AND SCENARIOS
- Events
- Incidents
- Scenarios
In Chapter 8, formal methods of event tree and fault tree analysis are used to understand the causal relationships that may exist. These cover a range of incidents that can be used to assess the overall impact of system failures. Another scenario could involve a series of incidents Ij (j - 1, .. , m) that could have purely ecological consequences for air or water resources.
EFFECT AND VULNERABILITY MODELS
- Consequence Analysis for Eco-Systems
- Major Effects in Consequence Analysis
Sources can be acute and chronic, and COC is released into the environment in many ways. Models for COC receptor uptake are needed at this stage as well as the determination of ecological endpoints. Of importance here is the level of thermal radiation produced by the flames and the duration of the radiation.
