In this article we will acquaint the reader with the meaning of reservation in the broad sense of the term. Its types, general presentation, relationship with natural phenomena and much more will also be considered.
Introduction
Redundancy is a universal principle that ensures the reliability of any type of system. Such types of systems are widely distributed and used in nature, technology and engineering.
Reservation types include:
- hardware form of redundancy, a prime example of which is duplication;
- informational type of reservation, such as a technique that detects errors and correlates them;
- temporal redundancy, which can be observed in the technique of an alternative kind of logic;
- program type redundancy is represented by functionally equivalent programs.
Technical systems
By definition, redundancy should be considered as a method that improves the performance and reliability of a particular device, mechanism. And also with the help of this phenomenon, you can support the device ona certain, necessary level, by including a spare set of elements and communication. However, this is an additional support measure, imposed additionally.
This concept can be considered both in a narrow sense, for example, booking tickets, and in a broad sense, for example, the use of backup mechanisms at industrial facilities. However, in both cases, this will be a way to prevent possible failures in the future development of events that would lead to a violation of the integrity of the system in the long term. The main reason for the need to have backup methods to maintain the system in a state of norm is dictated by a set of requirements for state industrial safety. Reservation is also of great importance in equipment designed for military craft.
Through this phenomenon, the safety of nuclear power plants is brought to a level with physical separations and a variety of types of equipment designed to implement the most important principles of a single failure mode.
Security systems for such important facilities as nuclear power plants have a triple redundancy option. The latest Russian projects, implemented during the construction of the Tianwan NPP in China, have a quadruple redundancy.
A device element related to minimized structures, which ensures its ability to do work, is called the main one. Reserve elements are parts, purposewhich lies in ensuring the operability of the mechanism, due to the failure of the main parts.
In a technological system, redundancy can be classified according to a set of features, the main ones being the height of the redundancy level, multiplicity, the state of spare elements before they are put into operation, the ability of main and reserve parts to work together.
Failure of a part of the system in a product intended for reserve can occur only after the main device and all spare elements of the system are out of working order. A group of elements can be called redundant, in which the failure of one of them or even more will not lead to a breakdown of the entire system. All parts of the mechanism capable of performing their functions will continue to do so, and the work of the missing parts will be taken over by the backup device. This replacement method is called functional redundancy.
In accordance with the scale and unit of calculation, the following types of reservations are distinguished:
- general, in which the reserve is necessary to continue working only in case of failure of the entire object;
- separate, in which the reservation of individual parts of the object takes place;
- private, providing for the reservation of a group of the same set of elements.
Analyzing redundant systems, a person came to the conclusion that the level of failure rate of a redundant object increases with increasing time. The non-redundant structure has the same power of influence of time on the probability of failure in accordance with the redundant one. However, this is notindicates that the absence of a breakdown in the system and, therefore, not using the stock can justify its absence until the system fails. Based on an understanding of this phenomenon, it can be concluded that redundancy makes sense in systems required for short-term operation, and a critical system must be secured using other reliable methods.
It is important to take into account the peculiarity of the purpose of the backup system. This is because the method used for a digital system with a continuous activity type will be of little use for a system with an analog type device. Because of all this, there is a problem with creating a backup method for all systems at once.
There is a method for evaluating the effectiveness of redundancy, in which, using the coefficient responsible for increasing reliability, the reliability indicators of the ratios are calculated:
yp=P (t)p / P (t)
γQ=Q (t) / Q (t)p
In such calculations, P(t) and Q(t) indicate the possibility of fail-safe operation and the chance of failure for the reserve system.
P (t) and Q (t) are the height of the probability of failure-free operation and the probability at which a failure of a non-redundant type of system will occur.
General type
In a general reservation, the stock is made immediately for the entire system. Depending on the way in which the redundant device was introduced, the overall redundancy can be considered permanent and replacement. Whenapplication of the general type of reserve, spare devices are connected to the main ones and remain included in them throughout the entire operating mode.
Permanent type reservation
Permanent redundancy is a form of stock in which there is a relatively simple construction scheme, there are no interruptions in work even in case of failure of some element.
The obvious disadvantage of a loaded reserve is the increase in energy consumption and the "aging" of spare elements along with the main ones. As a result, the need to replace elements of the main composition will determine the availability of replacements and spares.
Replacement
When reserving funds, any objects that can be used to restore the system when it fails, this process can occur by replacement.
Reservation by substitution method can be performed by another automatic type system or by human hand. In the case of using automatic intervention, it is necessary that the machine that performs the work has high reliability. Using manual element replacement increases the time spent on switching. However, the high reliability of the operator replacing the part can be taken into account when comparing the work of man and machine.
Reservation split
Separate type of redundancy provides for the introduction of an individual reserve intended for all parts of the non-redundant type of system. It is divided into general and substitutive. Separate substitutionis characterized by the probability of a failure in the system only if the failure occurs twice in one place. Mathematical analyzes show us that the use of split redundancy will give a higher indicator of system reliability.
Relationship with biology
In biology, reservations can be tracked by observing animals. For example, an organism whose place lies at the beginning of the food chain takes advantage of the reservation to ensure the reproduction of the species in the plural by means of high fecundity. A herbivore, in the majority of cases, has more offspring than a carnivore.
Reservation is a precaution that is widely used by our body. An example is the duplication of organs of the external type (two eyes, hands, ears and nostrils). Remembering the internal organs, one can note the duplicated sex glands and kidneys. The presence of this phenomenon in the body can increase its functional set of capabilities. Duplicated human eyes make it possible to realize vision in stereoscopic form.
The science that studies redundancy in living systems is called bionics.
Reservation and organizational systems
In the organizational system, redundancy is the presence of a subject capable of performing the duties of the head of the entire object, project or enterprise, at the time of the absence of the head. For this, deputies are appointed to responsible positions. In most cases, there isseveral deputies responsible for different functions of the head.
Organizational systems, like the army, use the concept of a reserve, which is in fact a reserve of personnel.
Conclusion
Stock can be called a synonym for the word "reservation". This phenomenon is widely used by all types of living and mechanized systems and underlies many of the most important biological phenomena and processes. There are many ways to perform the action in question, each of which has its own specifics and significance. The reservation has an unusually large diagram of the spectrum of the parts of all living things, to which it can spread.
