Risk assessment of technical systems. Fundamentals of risk analysis and management methodology

2024 Author: Howard Calhoun | [email protected]. Last modified: 2023-12-17 10:16

Assessing the risk of technical systems and making adequate decisions is an actual everyday practice, in which the right decision is essential and always determines adequately objective consequences, which does not always correspond to a reasonably justified calculation.

All technical systems that have ever been created operate on the basis of objective laws, primarily physical, chemical, gravitational, social. The level of qualification of a specialist, the level of development of the theory and practice of risk analysis and management are certainly important, but they do not always objectively reflect reality.

Background, theory and cost of risk assessment

The variety of technical systems is determined by the multiplicity of types of production activities, differences in industrial facilities, their relevance to the spheres of lifehuman.

Technological risk analysis considers likely negative consequences:

• failure of technical systems,
• failures in technological processes,
• errors of service personnel.

It makes good sense to consider negative impacts on people and the natural environment.

Even accident-free operation of industries (emissions, leakage of harmful substances, untreated effluents, etc.) may lead to the need for risk assessment by various parameters and consequences.

The human factor in risk assessment

The results of the application of the technical system in the context of the expected risk are essential for making informed decisions:

• determine placement;
• design of production facilities;
• transportation and storage of hazardous substances and materials;
• energy supply (gas, electricity, compressed air);
• and other things.

In the study of risk, formal methods and algorithms are used, various situations are taken into account that management and operating personnel may encounter.

Uncertainty is a characteristic quality of the application of a technical system. In many cases, the decisions of a specific specialist are made, which leaves an imprint on the methodology, course and results of risk analysis.

The environment for the existence of technical systems

Usually technicalsystems are created by people. The ideas of nature and the initiatives of aliens usually do not carry such a share of risk and do not require such close attention as the creations of human hands.

Reliability of technical systems and man-caused risk of a task are determined by the scope of its application. For example, a house and its engineering structures are always associated with the territory, its features, climate, the influence of other technical systems, human activities, etc.

Natural phenomena affect technical systems not intentionally, but objectively. People may have no idea that as a result of their "reasonable" actions, this house or its engineering structures may be in an unforeseen situation.

As a result of the construction of a new house, which will add pressure to the engineering structures of the territory, existing technical systems may suffer. As a result of a hurricane, for example, a roof can be blown off or structural damage can occur.

Houses built by specialists accustomed to the characteristics of a certain area can cause significant damage to the area, which places special demands on the foundations of structures, in particular.

Operation of an aircraft by experienced pilots on familiar routes will certainly lead to unforeseen situations when it crosses mountainous terrain or in flight over territories where the atmosphere is characterized by pressure drops, air currents, etc.

Assessing the risk of technical systems and the environment of their "existence" is a task, the relevance of whichis growing every day. And the complexity of this task is proportional to the speed of creating new technical systems and new options for influencing existing systems.

The emergence and development of technical systems

The normal life of a person and the performance of the mechanisms he created has never gone beyond reasonable need and real possibilities.

The car replaced the horse, and the advent of the railroad, ships and aircraft changed the infrastructure for transporting goods and passengers. Any technical system does not stand still, and its functionality and applicability reflects its technical capabilities against the background of the current environment and other technical systems.

Both the system itself and its functionality only in very rare cases lie within the competence of its creators, much more often it is superimposed by the activities of those who operate, repair, modernize, supplement, complete construction …

Real examples of risks in this natural development process (by source):

• natural phenomena;
• human factor;
• technical systems;
• socio-economic environment.

They cause the consequences of varying degrees of severity, that is, they form the need to "do something" in order to maintain the required functionality and restore the operability of a technical system that has been affected by a natural phenomenon (flood, landslide, earthquake, …), which was damaged by the actions of people, the impact of another technical system, or found itself without “means toexistence”, when the socio-economic situation around changed dramatically.

There are many options for influencing the current system. Risks arise both when a person does nothing, and when he assesses the state of affairs and takes measures to increase the reliability of technical systems and reduce man-made risk.

Progress in systems and the development of risk assessment theory

Scientific and technological progress has long led to the fact that a person consciously began to form a scientific foundation in the field of risk analysis and assessment. Scientists have long argued that "Risks and dangers in the development of civilization have been, are and will be … you will have to accustom yourself to the idea of the need to live under this burden … this means only one thing: humanity needs to learn how to minimize this risk and danger."

Usually risk analysis methods are understood as:

• statistics;
• value for money;
• expert evaluations;
• analytics;
• analogy (use of analogues);
• financial sustainability;
• impact analysis;
• combined options.

It works, but not always. The current stage in the development of public consciousness, the number and complexity of existing technical systems is so great that it is often difficult to talk about the real qualified influence of a person on a particular system, which does not cause the emergence of a new risk or real danger.

However, it is developmentrisk analysis and assessment methodologies, the accumulation of statistical data and actual experimental material during operation has led to the fact that the reliability of technical systems and risk assessment have become indispensable components both in the creation of new systems and the development of existing ones.

Self-developing systems in statics

It is often strange to hear that the basic design of an airplane or ocean liner was created in the last century. But to create a radically new aircraft or liner today from scratch is absurd, and at this point in time, not a single qualified specialist would offer anything completely new.

The knowledge of the last century, like the theoretical developments of Archimedes, is fundamentally useful. They build a modern understanding of things and their functionality. This is normal and natural. And it works, providing conscious risk management, provides a mathematical apparatus for determining the reliability of a particular system, for assessing the risk of an unforeseen situation and its consequences.

A completely different scenario is given by systems that become an integral part of human life, in addition, are continuously improved by a mass of people. It is so difficult to assess risks, perform analysis and predict the development of the Internet, web resources, programs. These technical systems do not work as intended by the author (development team).

Self-developing systems in dynamics

A programming language today is not the application that its creators planned at the time of implementation, the release of new versions. The programmer uses the programming language within his competence and experience. He is least interested in the ideas of the creators of the language.

But a mistake made by the developer of a tool can harm the system that the programmer has created with that tool. Most often, the user of such a system will cause damage by using it differently than the programmer intended.

These circumstances lead to actions to prevent the negative impact of the system without the participation of its creator, and even more so without the participation of the tool developer. In this context, risk assessment of technical systems takes on a different meaning:

• there is a tool to create a technical system;
• there is a system created by means of a tool;
• there are many applications of the system in various fields;
• there are many implementations of adapting the functionality of the system;
• there is a problem of choosing the optimal adaptation and its reverse effect on the system and the tool for its creation.

To put it simply, the knowledge of some specialists has turned into a technical system, this is how it separated from the creator. This knowledge has been applied in practice and acquired many options for use, which entailed not only new knowledge, but also specific new implementations of the system. The new knowledge has separated from its developers and created a reason for it to be pooled for the purpose of analysis and evaluation to impact back on the system.

Redundant systems for improved reliability

Safety andReliability has always been a key term in the design and use of any system. Moreover, the level and degree of responsibility of the system, as a rule, does not play a special role. The study of the reliability and risk of a non-redundant technical system is of greater importance.

An oil refinery and a conventional water faucet are completely different systems, but the study of the safety, reliability and risk of a non-redundant technical system is relevant in both cases.

Reserving the system as a whole or in part of its specific element is not always advisable, and often fundamentally simply impossible.

But reservations can be made in various ways. Some elements of the systems can simply be changed entirely and this will be the ideal solution. Some systems simply need to be replaced with new ones based on experience with previous models, but not necessarily homogeneous.

Systems theory, risk assessment and management methodology has never been a dogma since its inception. As systems of knowledge based on experience, statistics and the intuition of specialists, they represent a dynamic potential that is applied in each situation in an individual way.