SUMMARY
This article seeks to make known in a practical way what reliability is in the field of engineering, mentioning and a brief explanation of each of the general and basic concepts that are useful to give first-time knowledge on this subject. As well as its importance for the field of engineering and aspects other than it, such as everyday life. A bit of history is also presented and a comparison with the life of the products is shown to show their application and value.
KEYWORDS
Reliability, Reliability Engineering, Reliability Analysis, Failure.
GENERAL CONCEPTS
Components
In everyday life people make use of products and services which are simple, like a glass, or complex like a computer. However, they are all made up of components. The simplicity or complexity of the products will depend on the number of components of which the product is made. The greater the number of components, the more complex it will be.
A component can also be formed thanks to the sum of several sub-components. But regardless of the number of subcomponents that make up a finished product, it will be considered a single component.
A clear example of the products and their components can be the computer which is made up of Hardware devices that are essential for their correct operation, some of these are the keyboard, the CPU, the monitor, the mouse among others and in turn each one of these components is made up of other subcomponents. Sometimes also the sum of components can be considered a system, therefore sometimes words system and components can become equivalent.
Failure
It is called failure to the situation in which the component of a product a system stops fulfilling its functions either partially or totally. Or also a considerable difference between expected performance and actual performance. Failures can occur due to product defects, that is, technical or physical defects that include poor product design, the use of unsuitable materials, an improper manufacturing or construction process, problems in assembly, and maintenance. among others.
Although they can also be caused by operational or procedural errors, including inadequate management of the quality process and failures in the process related to the human factor.
Types of failures
The fault classification is very extensive and is divided into various groups of parameters whose characteristics are similar. Some of the criteria on which reference is taken to divide or classify failures are:
- The degree of influence on the work capacity The physical character of the appearance The character of the appearance process The time of existence of the fault The moment of appearance of the fault The fault information Causes Nature Duration Extent Variability
Among many others. As mentioned above, these are just some of the classifications among which failures can be classified, however each classification has different types within each of them, which makes the study of the types of failures very extensive. (Castaño, 2014)
IMPORTANCE OF THE MINIMIZATION OF FAULTS.
The failures that can occur in the components of the products or services and can cause effects ranging from the minimum such as annoyances to the user to major problems such as a great impact on society or irreversible damage to the environment. Corrective treatment of failures is useful, however, it is appropriate to maintain procedures that avoid as much as possible the failures that the components may present.
For this, it is necessary to talk about three points that make it possible to minimize component failures: quality, safety and reliability. These three factors are mentioned for two reasons: the first is because the importance of minimizing failures lies in the conjunction of these three factors, and the second is to explain them to avoid confusion between the concepts.
Quality: Quality is understood as the performance of the product or service compared to previously established technical standards. Some examples within which quality can be mentioned may be within the food industry, the cable television signal, the internet, the quality of materials within a civil engineering work, among others. That is, how good the material is compared to the standards indicated by the company.
Safety: This term refers to the fact that the products or services do not imply a danger or potential risk to the health of users, the environment, the company or society. The food industry also enters here (colorants, flavorings, binders, among others), toys for children, medicines, household products, among others.
Reliability: What this word means is that a product or service must fulfill its function for a previously estimated time under the operating conditions previously classified.
That is, while safety invites risk minimization, quality is directed towards the composition of the materials and reliability is directed towards the durability of the final product, that is, the set of components.
WHAT IS RELIABILITY?
It is the probability that a component or system can fulfill its function under specified operating conditions during a given time interval. (García, 2014)
It is the probability that a component or system can fulfill the required function without failure under established conditions and during a specified period of time. More generally, reliability is the ability of components or systems to perform their required function for desired periods of time without failure, in specified environments, and at a desired confidence. (Castaño, 2014)
HISTORY OF RELIABILITY
Reliability as a concept emerged around the 1940s and 1950s. And it emerged after World War II because militants required an estimate of the number of spare parts needed to keep both electronic and mechanical equipment working properly for long periods of time. weather.
Over the years and the beginning of space exploration increased the need for the development of a methodology that would make the components (satellites, probes and vehicles) and systems that allowed the activities of NASA and other institutions that were to be carried out more reliable. dedicated to the study of the cosmos. At the beginning of the seventies, the oil crisis generated a change in the world economy and Japan marked the beginning of its leadership in quality by implementing reliability methodologies in products and services that assured its authority in the matter.
Currently, companies face fierce competition within a highly globalized market, which does not allow them to have much margin for error because if so, users would prefer the products of the competition, running out of an opportunity in the market. So they are pressured to maintain high expectations for quality and reliability in the products or services they offer. (Escobar R., Villa D., & Yañez C., 2003)
RELIABILITY ENGINEERING
It is the set of methods, techniques and tools that serve to determine the degree of security in which a device, product or system will work in optimal conditions during a certain period of time. (García, 2014)
That is, it is the set of methods that allow the calculation and later the comprehensive application of reliability.
TYPES OF RELIABILITY
The type of reliability that is chosen to treat a product or service depends on many factors. But broadly, it can be determined that the type of reliability will depend directly on the part of the system that needs to be improved.
Reliability Engineering is present through a Maintenance Plan in which the guidelines to be followed are drawn up to minimize failures or maximize the use of the product itself. This begins with operational reliability, which in turn is divided into reliability subtypes more focused on a specific area.
Operational reliability
It is the capacity of a system to carry out its specific operational functions relating the part of the assets, processes and people.
Design reliability
It can be defined as the consideration of the possible scenarios, risks and threats that the design of a product or service represents and its future use in order to minimize failures or optimize operation.
Equipment reliability
Set of tools applied to lead to the improvement of the duration of the equipment in correct operation under certain specific operating conditions
Process reliability
It is the technique that allows us to know and determine the parameters of an organization's operations, thus having a precise understanding of them.
Human reliability
Set of knowledge and techniques that are applied in the prediction, analysis and reduction of human error, focusing on the role of people in the areas of design, operation, processes, maintenance and management of a production asset. (Gutiérrez, 2016)
PRODUCTS LIFECYCLE
The analysis of the reliability of the products is closely linked to the life cycle of the products, since the types of reliability are focused on the parts of the development of a good in order to establish reliability values within each of the stages and customer satisfaction can be maximized. The life stages of a product that are considered within reliability are the following:
Conceptual product design
In this part of the process, the collaborators focus on discovering what they are going to elaborate regarding the client's requirements and therefore they are the first attempts to minimize product problems in addition to ensuring that manufacturing is viable.
Detailed development and preliminary prototypes
Once it is considered that the product is viable, the required production resources are detailed and the corresponding improvements are made based on the results of the conceptual design tests. It is in this part where it is tried to minimize in detail flaws that can prevent the manufacture of the product or that hinder its use.
Pilot testing and production
It is the part where the good is physically made and some failures are generated that were not planned to be corrected during the march. It should be noted that the conceptual failures that occur in the laboratory are not the same as those that occur in the field, and these can only be visible at the time when the good is being produced or, failing that, when it is exposed to the true useful environment.
Product use
This stage is reached when the good or product is placed in the hands of the final consumer. It is necessary to establish a strategy that allows the customer to collect complaints regarding failures that occur once the product leaves the factory, since it is important information that allows improving both physical and functional characteristics.
Product failure can occur in any of these stages and in different types, as well as occurring at different times and circumstances. The failures that occur will depend on the type of product or service that is being generated and also on the feedback that is had with the end customer.
BENEFITS OF RELIABILITY
- Failures generate extra costs as well as general losses to the company, so it can be determined that a comprehensive reliability plan applied can reduce these costs, reducing the bad corporate image that an organization may have due to the fact that its products fail a lot. The product meets the expectations of the customers on the functionality and useful life of the equipment. It maximizes and ensures the operation of the product in certain specific conditions. It generates confidence regarding the product, that is, it can be ensured that what is offered It is safe and of quality. It reduces the foreseeable risks inherent to the operation of the product and also the dangers that it may represent.
HOW TO IMPROVE RELIABILITY?
The reliability improvement system can be carried out through different methods, techniques and tools that will depend on various factors and variables which influence the decision-making process for choosing the correct method. Some examples of these variables can be the area to which you want to focus reliability engineering, the product you are trying to improve, the type of failure you are trying to minimize, the time you have available to implement the methodology, the part of the process development of the product that is being worked on, among others.
There are two basic ways in which the reliability of a component or a system can be improved. The first one is through quality, that is, focusing on the configuration of the product components. This is carried out through the analysis of the materials used as well as the treatment prior to their manufacture, carrying out tests for calibration, transport and commissioning.
The second of them is through redundancy, which is the fact of placing backup elements in case the component fails, and in this way the function is assumed by the backup component. There are two types of redundancy, the active one where the redundant component is always connected in parallel with the main component and the Stand By one where the redundant component is connected when the main component fails. Other methods can be preventive maintenance, the diversity of components, spare parts in stock, among others.
Reliability ratings
The measurement, comparison and evaluation of reliability is given by reliability indices which allow to appreciate the numerical and objective values on which reliability can be supported, to determine a position. Some examples of these measures for reliability are the average life of a product, the frequency of failures per year, the unavailability, the loss of load, LOLE (expected value of loss of load), LOLP (probability of loss of load), ENDURANCE, among others. (Zapata & Campos, RELIABILITY ASSESSMENT OF GENERATION SYSTEMS WITH LIMITED ENERGY RESOURCES USING MONTECARLO SIMULATION, 2005)
Analysis types
- For your evaluation of numerical data:
Quantitative.- It does not evaluate numerical data and the assessment is subjective.
Qualitative.- Evaluates numerical data and the assessment is objective.
- By the type of behavior of the variables
Deterministic.- Where the variables are fixed and maintain a certain value for any instant of time. There is no uncertainty.
Probabilistic.- Where the variables are random and do not have a fixed value and there is no function that allows us to determine their value at a given instant of time. There is uncertainty.
- By the type of study model
Analytical.- The component or system under study is represented by means of a mathematical model (equation or set of equations) and the reliability indices are evaluated by means of direct mathematical solutions. Some examples of these methods can be: Block Diagrams, Markov Process.
Simulation.- The random behavior of the component is simulated to subsequently evaluate the reliability indices indirectly by means of numerical techniques. Example: Monte Carlo method.
- By temporality
Historical.- The component or system is studied based on the data of past operating behavior.
Predictive.- Through information processing, the behavior indices of a component or system are predicted for an instant of time or future period of time. (Zapata, Reliability in Engineering, 2011)
CONCLUSION
The technological revolution that the world has gone through in the last fifty years has made industries feel the need to look for tools that allow them to be more efficient in order to stay in the market. Reliability engineering is a tool that has achieved this objective as it allows organizations to take their products to another level of improvement, assuring the customer that they have made a good decision when making the purchase or consumption of the products by offering the safety of use and its quality.It is worth mentioning that under these two concepts of quality and safety, not only organizations but also the consumer benefit, since anyone is interested in the reliability of the products they use in daily life, such as the operation of the air bag in the car., the security of the gas supply and the reliability of the banking information system, showing quickly the great importance that this issue has for society in general.
RESEARCH PROPOSAL RELATED TO THE TOPIC
Analysis and application of a Reliability Engineering method to an area of the administrative system of the Technological Institute of Orizaba.
Objective:
Measure the quality offered by the system and implement the most appropriate Reliability Engineering method to improve the level of quality and service.
THANKS
The preparation of this article is part of the study of the Master in Administrative Engineering that the author is doing, therefore she thanks Dr. Fernando Aguirre and Hernández for assigning the activity; to the National Technological Institute of Mexico and CONACYT, for their support in carrying out these studies.
REFERENCES
- Castaño, SR (2014). ANALYSIS OF FAILURE DATA. Manizales, Colombia: National University of Colombia, Manizales Headquarters. Faculty of Engineering and Architecture Escobar R., LA, Villa D., ER, & Yañez C., S. (2003). RELIABILITY: HISTORY, STATE OF THE ART AND FUTURE CHALLENGES. Dyna, vol. 70, no. 140, pp. 5-21.García, LG (November 12, 2014). Gestiopolis. Retrieved October 22, 2017, from https://www.gestiopolis.com/ingenieria-deconfiabilidad-1/Gutiérrez, KY (May 12, 2016). Gestiopolis. Retrieved October 22, 2017, from https://www.gestiopolis.com/ingenieria-de-confiabilidad/Zapata, CJ (2011). Reliability in Engineering. Dosquebradas, Colombia: Publiprint Ltda. Zapata, CJ, & Campos, EL (2005).RELIABILITY ASSESSMENT OF GENERATION SYSTEMS WITH LIMITED ENERGY RESOURCES USING MONTECARLO SIMULATION. Scientia et Technica Year XI, No 29.
