Lecture number 3. Wear of equipment parts. Types of wear.
Wear - gradual surface destruction of the material with a change in the geometric shapes and properties of the surface layers of parts.
There is wear:
Normal;
- emergency.
Depending on the causes, wear is divided into 3 categories:
1. chemical;
2. physical;
3. thermal
Normal wear - dimensional change that occurs in a short time due to improper installation, operation and maintenance.
Chemical wear - consists in the formation of the thinnest layers of oxide on the surface of parts, followed by exfoliation of these layers. The ongoing destruction is accompanied by the appearance of rust, metal corrosion.
Physical deterioration - the reason may be:
Significant loads;
Surface friction;
Abrasive and mechanical impact.
And at the same time, the details appear:
microcracks;
cracks;
The metal surface becomes rough.
Physical wear is:
Smallpox;
- tired;
- abrasive;
Thermal wear - characterized by the formation and subsequent destruction of molecular bonds within the metal. Occurs due to high or low temperature.
Reasons for wear:
1. The quality of the material of the parts.
As a rule, for most parts, wear resistance is higher, the harder their surface, but not always the degree of hardness is directly proportional to wear resistance.
Materials with only high hardness have high wear resistance. However, this increases the likelihood of scratches and detachment of material particles. Therefore, such parts must have a high viscosity, which prevents the detachment of particles. If two parts made of homogeneous materials experience friction, then with an increase in the coefficient of friction they wear out quickly, therefore, more expensive and difficult to replace parts must be made from a harder, high-quality and expensive material, and cheaper simple parts should be made from a material with a low coefficient of friction.
2. The quality of the surface treatment of the part.
There are three parts wear periods:
The initial period of running-in is characterized by a rapid increase in the gap of movable joints;
- the period of steady wear - there is a slow, gradual wear;
A period of rapid, increasing wear - caused by a significant increase in clearances and a change in the geometric shapes of parts.
To increase the service life of parts, you must:
To shorten the first period as much as possible, by very precise and clean processing of parts;
Increase the maximum second period;
Prevent the third period.
3. Lubrication.
A layer of lubricant introduced between the rubbing parts fills all the roughness and irregularities and reduces friction and wear many times over.
4. The speed of movement of parts and specific pressure.
On the basis of experimental data, it has been established that under normal specific loads and speeds of movement from 0.05 to 0.7, the oil layer does not break and the part works for a long time. If you increase the load, then the wear of the part will increase many times.
5. Violation of rigidity in fixed parts.
6. Violation of landings.
7. Violation of the mutual arrangement of parts in mates.
In mechanical engineering, there is a system of standards that regulates the collection and accounting at enterprises of information about the state of the machine, its damage and failures, as well as the cost of repairs. Therefore, the appraiser almost always has the opportunity to use this information to more accurately describe the condition of the machine when determining its physical deterioration.
As a result of physical wear:
- * the technical characteristics of the object and operational characteristics are deteriorating;
- * increases the likelihood of breakdowns and accidents;
- * the residual service life of the object as a whole or some of its components and parts is reduced.
When evaluating machinery and equipment, the determination and accounting of depreciation is necessary due to its significant impact on the value of the objects of assessment. Usually, the wear and tear of a machine, primarily physical wear, leads to a deterioration in technical performance, which inevitably affects its cost. In general, the cost ( WITH ) and physical wear and tear of the machine are connected by a simple relationship:
As can be seen from formula (11), Key physical represents the proportion of the reproduction value that the machine has lost due to physical wear and tear.
The loss by the machine of its initial performance during operation is an inevitable process that proceeds with greater or lesser intensity, depending on the design of the machine and the conditions for its use. The limiting state here is the moment when these indicators go beyond the permissible limits.
Starting from this moment, the machine needs to restore its performance, which is achieved by repairing its components and elements, upgrading, replacing worn parts, adjusting, etc.
No machine, no matter how perfect, can do without repair and maintenance, which are an integral part of its normal operation.
To restore the working capacity and slow down the processes of wear of machines, various systems for organizing their repair are used. However, the basis of any such system in the enterprise is usually made up of periodic scheduled repairs, which are carried out at regular, predetermined intervals. Such a system is called a system of preventive maintenance (PPR).
The cost of restoring the machine is reflected in the accounting of the reporting period to which they relate. At the same time, the costs of modernization after it has been carried out can increase the initial (replacement) cost of the machine if, as a result, the originally accepted standard indicators of the machine’s functioning (useful life, productivity, quality, etc.) improve.
To assess the state of equipment and machines, their performance and identify elements that affect the output parameters, methods of technical diagnostics are widely used. The diagnostic parameters by which the state of an object is usually judged and which can be controlled during its operation are:
- * Output parameters of the object that directly characterize its performance. For machine tools, these are, first of all, the parameters associated with the accuracy of processing - the errors in the trajectories of movement of the working bodies; for cars - braking distance, engine exhaust and steering play; for tractors - engine and running gear failures, etc.
- * Damage to machine elements that occur during the operation of the facility and can lead to failure. In machine tools, these are the wear of movable joints, especially those that are poorly protected from pollution, poorly lubricated and operate under conditions of dry friction; for automobiles, these are the wear of brake pads, elements of the engine piston group, as well as joints in the steering and suspension mounts.
- * Signs of deterioration in the condition of the machine associated with output parameters. These include an increase in noise during machine operation, an increased temperature of friction units, and the presence of wear products in the lubricant. The use of diagnostic methods requires a variety of measuring instruments and serious preliminary preparation.
When evaluating the cost of expensive and unique machines, the information obtained using the methods of technical diagnostics is extremely valuable, since on its basis experts can draw reasonable conclusions about the level of wear of the machine as a whole.
However, when evaluating machines, especially mass ones, the use of methods for direct assessment of physical wear and tear is difficult for the reasons indicated above. In addition, their application does not give the appraiser a direct answer to the question of the impact of the condition of the machine on its value.
The existing methods for determining physical wear used in the assessment are based on:
- a) preventive maintenance and preventive maintenance standards developed for different types of machines, equipment and vehicles;
- b) standard service life under specified operating conditions.
At the industrial enterprises of Russia there is a system of preventive maintenance of equipment. Information about the state of the machine is recorded in the repair department of the enterprise. The availability of such information allows the appraiser to assess the physical wear and tear of the machine.
The following methods are known for determining the degree of physical wear of machines when evaluating them:
- * method of physical condition examination;
- * method of effective age (service life);
- * weighted average chronological age method;
- * expert-analytical method;
- * method of deterioration of the main parameter.
Method of examination of the physical state of the object
The point in applying this method is to compare the object of assessment with one of the many descriptions of its possible technical conditions in which it may be as a result of wear. Typically, such a set has the form of expert scales or tables, the rows of which correspond to various states and stages of wear of the objects of assessment, indicating the corresponding coefficients of physical wear (Ki, fiz.)
An example of such a scale is given in Table. (2). In order to relate the wear of a machine to its cost, scale tables for determining wear rates are usually built on the basis of processing statistical information about the prices of new and used machines. The values of wear coefficients are determined by comparing sales prices ( color) in the secondary market of machines, the technical condition and physical wear of which is known, with prices ( C) new identical cars.
In this case, the wear factor can be found as;
The appraiser, as a rule, is able to apply the method accurately enough only in situations where he is well acquainted with the object of assessment. In other cases, when determining the coefficient of physical wear (Ki, fiz.) By this method, the appraiser may involve qualified specialists in the field of equipment operation for consultations on its technical condition (independent experts). In this case, the reasoning of the specialists' answers and information about the sources of this reasoning are very useful for the evaluator.
To increase the reliability of the assessment (Ki, fiz.), the opinion of several experts can be taken into account, especially when it comes to choosing a value from a fairly wide range of values within one row of the table. In this case, the evaluation result is the weighted average of the experts.
Effective age method
To assess wear, the concept of effective age is introduced ( tef) equipment. If the chronological age ( T)-- is the number of years that have passed since the creation of the machine, then the effective age ( tef)-- this is the age corresponding to the physical condition of the machine, reflecting the actual operating time of the machine over the period ( T) and taking into account the conditions of its operation. Knowing the effective age of the object of assessment allows you to more reasonably judge its wear.
If the effective age ( tef ) machine is known, then the coefficient of physical wear is determined by the formula:
Usually to determine TEF expert evaluation of remaining service life Toast object of assessment before its withdrawal from operation and write-off. In this case:
Teff \u003d TN - Toast. (15 )
The determination of the remaining life assumes that the estimator knows how the machine will be used from the time of valuation until the very end of its service life (shifts, loads, operating conditions, etc.).
Expert-analytical method
The method involves determining the coefficient of physical wear of the machine while simultaneously taking into account its chronological age and an expert scoring of the physical condition. In this method, the depreciation coefficient is obtained on the basis of prices for used and new machinery and equipment, that is, it reflects the reaction of the secondary market to the degree of physical depreciation of the MO.
Weighted average chronological age method
The method can be applied when, after several years of operation of the machine, a number of units and parts have been replaced, and their age turned out to be different. In this case, the coefficient of physical wear and tear can be calculated by the formula:
Principal parameter degradation method
The method assumes that physical wear manifests itself in the deterioration of any one characteristic operational parameter of the machine (productivity, accuracy, power, fuel consumption, etc.). If such a parameter is found for a given type of machine, then the coefficient of physical wear is calculated as follows:
A significant share of the costs of the enterprise - the costs associated with the use of machinery, equipment, production facilities. Their use has a characteristic feature: unlike material resources, they are not consumed in one production cycle. Capital resources last for years and wear out.
Depreciation of equipment is the loss of its value and performance. Wear and tear can occur due to many reasons: aging of equipment, loss of its competitiveness, etc. Today, the fight against wear and the extension of the service life of equipment is a very urgent task.
Depreciation in the economic sense means the loss of value of the equipment during its operation. In this case, two types of wear are distinguished: physical and moral. Physical wear occurs due to equipment aging and loss of its performance, and moral wear due to loss of competitiveness.
Physical depreciation is the loss of fixed assets of their original consumer value, as a result of which they become unusable and require replacement with new funds. This is normal wear and tear. It is the result of past periods of operation, environmental influences and downtime. As a result of physical wear, the technical characteristics of the object worsen, the probability of breakdowns and accidents increases, the residual service life of the object as a whole or some of its components and parts decreases. This leads to an increase in waste, the risk of serious accidents, the inability of machines and equipment to meet the requirements for proper functioning. Production costs (materials, energy), maintenance and repair costs also increase.
The physical type of wear is divided into subspecies:
- 1. For the reason that caused the wear, wear of the first and second kind is distinguished. Depreciation of the first kind accumulates as a result of operation. Depreciation of the second kind occurs due to accidents, natural disasters, violations of operating standards, etc.
- 2. According to the flow time, wear is divided into continuous and emergency. Continuous is a gradual decrease in the technical and economic indicators of objects. Emergency - wear, rapidly flowing over time.
- 3. According to the degree and nature of the distribution, wear can be global and local. Global - wear, uniformly spreading over the entire object. Local - wear, affecting individual parts and components of the object.
- 4. According to the depth of flow, partial and complete wear are distinguished. Partial - depreciation, allowing repair and restoration of the object. Full involves the replacement of this object with another.
- 5. If it is possible to restore the lost consumer properties, wear can be removable and irreparable.
- 6. According to the form of manifestation, technical and structural wear are distinguished. Structural wear is manifested in the deterioration of the protective properties of external coatings and the increase in fatigue of the main parts and components of equipment, which increase the likelihood of accidents. Technical wear and tear is wear and tear, expressed in a decrease in the actual values of technical and economic parameters compared to standard or passport values.
To assess the degree of physical wear and tear, the following assessment methods are used:
- - expert method based on the examination of the actual technical condition of the object;
- - a method for analyzing the service life, based on a comparison of the actual and standard service life of the equipment.
Methods for calculating physical wear:
1. Effective life is based on the assumption of the reliability of determining the remaining life of the object (Toast). Calculated according to the formula:
Teff \u003d Tn - Toast
where Tn is the standard life span.
Physical depreciation Phi is determined by the following formula:
Phi \u003d Teff / Tn
2. Expert analysis. The following table is used to evaluate wear
Table 1
|
Physical deterioration, % |
Technical condition assessment |
General characteristics of the technical condition |
|
There are no damages or deformations. There are individual malfunctions that do not affect the operation of the facility as a whole and can be eliminated during the current repair |
||
|
Satisfactory |
The facility is generally suitable for operation, however, it requires repair already at this stage of operation. |
|
|
unsatisfactory |
The operation of the facility is possible only if repairs are carried out. |
|
|
emergency |
The state of the object is emergency. The performance of its functions is possible only when carrying out repair work or complete replacement of individual components and parts. |
|
|
Unsuitable |
The facility is in an unusable condition. |
3. Profit loss method (economic-statistical method).
Physical depreciation Phi is calculated by the formula:
Phi \u003d (Mon-Fri) / Po
where To - profit from the new object, Fri - profit from the object in the current state.
The values for Mon and Fri must be defined for a period (eg month, quarter).
4. Loss of productivity method (economic-statistical method)
Phi = ((Qo - Qt)/Qo)n
where Qo is the performance of the new object (passport characteristic), Qt is the performance of the object at the time of evaluation, n is the Chilton braking coefficient. For objects of the machine-building industry, it averages 0.6-0.7.
5. The method of the stage of the repair cycle.
This method is based on the assumption that the decrease in consumer properties of machinery and equipment during operation linearly depends on the operating time. At the same time, it is assumed that the repair carried out returns part of the consumer properties.
At the end of the repair cycle, that is, before the first overhaul, the value of the consumer properties of the PSr is calculated by the formula:
PSr \u003d PS - Kr * PS
where PS is the consumer properties of the new object, Kp is the relative decrease in consumer properties to the end of the repair cycle.
Accounting for the increase in consumer properties due to major repairs is carried out according to the formula:
PSr \u003d PS -Kr * PS + PS
where PS is an increase in consumer properties due to a major overhaul.
The calculation of physical wear (Phi) is as follows:
Phi \u003d (Pso -PSt) / Pso,
PSt \u003d PS - t * dPS,
t = M*D*Ksm*Kvi*Ts,
dPS \u003d (PSo - Kr * PS + PS) / Tr
where Pso is the value of consumer properties at the beginning of the repair cycle,
t - operating time after overhaul,
M is the number of months worked after the overhaul,
D is the number of working days in a month,
Kcm - shift coefficient,
Kwi - coefficient of intra-shift use,
Ts is the duration of the shift.
6. Method of element-by-element calculation.
When calculating wear using the element-by-element calculation method, it is necessary to represent the object in the form of several basic elements. Depreciation is determined for each element separately and is taken into account taking into account the share in the cost of the entire object. The wear calculation scheme is described by the formula:
Fip = fi*(ci/c)*(Ti/T)
where fi is the actual physical wear of the i-th element, ci is the cost of the i-th element, c is the cost of the object as a whole, Ti is the standard service life of the i-th element, T is the standard service life of the object as a whole.
The decrease in the value of capital goods may be associated not only with the loss of their consumer qualities. In such cases, we speak of obsolescence.
Obsolescence is understood as a decrease in the cost of equipment and other fixed assets until the end of their service life due to a decrease in the cost of their reproduction, as new types of fixed assets begin to be produced cheaper, have higher productivity and are technically more advanced. Therefore, the use of obsolete machines and equipment becomes economically unprofitable as a result of their low productivity and high cost.
The time of obsolescence and its degree are determined by the influence of many factors. First of all, these are the features and scale of production. Machinery and equipment, the use of which becomes unprofitable in some conditions of production, can be successfully used in others. In this case, we can talk about partial obsolescence of equipment. Losses from obsolescence can be eliminated by upgrading and refurbishing equipment, as well as using it to perform work where it remains cost-effective.
Losses from complete obsolescence are eliminated only by replacing obsolete machines and equipment with new, more advanced and cost-effective ones. Sometimes the improvement of existing equipment and machinery is more effective than its replacement. Therefore, a more rational way to reduce obsolescence is the modernization of machinery and equipment.
There are two forms of obsolescence.
Obsolescence of the first kind is due to the growth of the efficiency of production of capital goods. It is caused by the appearance of similar, but cheaper means of labor.
The amount of obsolescence of the first form (Im1) as a percentage of the total initial cost of the object (Zp) is determined by the formula:
Im1 \u003d (Zp - Sv) * 100 / Zp
where Sv is the replacement cost of the object.
Obsolescence of the second kind - depreciation of fixed assets due to the creation of new, more productive and improved equipment.
Obsolescence of the second form (Im2) is determined by the formula:
Im2 \u003d Zp - Zp / (Pr * Tn) - Zp1 / (Pr * Tn1) * To * Pr1
where Zp, Zp1 - the initial cost of the old and new equipment, respectively, Pr, Pr1 - the annual productivity of the old and new equipment, respectively, expressed in the number of products manufactured per year, Tn, Tn1 - the standard service life of the old and new equipment, respectively, in years, That is the remaining life of the old equipment in years.
Obsolescence of the second kind is associated with the emergence of new means of labor that perform similar functions, but are more advanced and productive. As a result, the value of old capital goods decreases.
Both forms of obsolescence are the result of technological progress. From the point of view of the national economy, this is justified, and even necessary, because as a result, obsolete equipment is replaced by more advanced ones, which means that the overall production efficiency increases. At the same time, for a particular enterprise, this positive phenomenon also has negative features: it turns into an increase in costs.
The gradual wear and tear of the means of labor leads to the need to accumulate funds to compensate for the wear and tear of fixed assets and their reproduction. This is done through depreciation.
Depreciation - compensation in cash for the cost of depreciation of fixed assets. It is a way of gradually transferring the value of funds to manufactured products. Deductions intended to reimburse the cost of the worn-out part of fixed assets are called depreciation. Depreciation deductions are accumulated, forming a depreciation fund.
The depreciation rate is the annual percentage of transferring the value of fixed assets to products.
There are two main methods of depreciation calculation: uniform (linear) and accelerated (non-linear).
Under the straight-line method, depreciation is calculated monthly based on its monthly rate. The latter is calculated by dividing the annual depreciation rate by 12.
The advantage of this method is its ease of use. However, it does not take into account the uneven depreciation of fixed assets in certain periods, and does not adequately contribute to the innovation process at the enterprise. In this regard, the method of accelerated depreciation of equipment deserves attention. There are several methods for calculating accelerated depreciation.
One of the most common is the method based on reducing the depreciation period and increasing its annual rates. In this case, depreciation charges in the first years of operation of fixed assets sometimes reach 40%. As a result of applying this method, enterprises quickly upgrade equipment and expand production based on the latest technology. A variation of this method of accelerated depreciation is an increase in the amount of depreciation deductions at individual enterprises in the first years and, accordingly, their decrease in subsequent years of using fixed assets.
Another variation of the accelerated depreciation method is the declining balance method.
The annual depreciation rate in this case will be twice as much as the depreciation rate under the straight-line method. At the same time, the declining balance method does not provide full compensation for the initial cost of labor instruments by the time the standard service life is calculated. To eliminate this shortcoming, entrepreneurs are allowed to switch to a uniform depreciation method from the second half of the service life.
fixed asset accounting depreciation
Since the start of operation, any equipment is subject to wear and tear, which increases with the increase in the life of the facilities and leads to the loss of part of their usefulness and, as a result, a certain part of the cost.
In valuation practice, it is customary to separate direct and indirect methods for determining the amount of physical wear and tear.
In other words, depreciation is the loss of value (depreciation) of property during operation under the influence of various factors of obsolescence and natural-temporal impact.
The causes of wear and tear can refer either to the object itself, or to the immediate environment of this object (the appearance of more advanced and competitive analogues, the emergence of new technologies or changes in the technological chain in which the object is included), or in areas that are not directly related to the object, then are external to it.
Physical deterioration, functional and economic obsolescence are usually considered as the main factors of impairment (obsolescence).
Physical deterioration- deterioration of the initial technical and economic properties, due to the natural wear of a particular object during operation and under the influence of various natural factors. In other words, this is the wear of the materials from which the object was created, the loss of its original qualities, the gradual destruction of structures, etc.
functional wear- a decrease in the consumer attractiveness of certain properties of an object, due to the development of new technologies in the production of similar machines and equipment. This decrease in attractiveness, in turn, causes impairment.
Functional obsolescence manifests itself with the advent of competing objects, and not gradually, like physical wear and tear.
For the reasons that caused functional obsolescence, obsolescence and technological obsolescence are distinguished.
Functional obsolescence is calculated using the formula:
K fun \u003d 1- (P o / P a) n
where: P o - the performance of the equipment being evaluated;
P a - performance of new equipment or equivalent;
n is the braking coefficient.
Obsolescence - this is wear and tear, the cause of which is an improvement in the properties of products similar to the one being evaluated (changes in technical parameters or design solutions, the emergence of new opportunities, greater environmental friendliness, ergonomics, etc.) or reduction in the cost of their production.
Obsolescence can be divided into three groups, based on cost items, changes in the structure of which depreciation is associated with:
1. Obsolescence due to excess capital costs (increased investment costs).
2. Obsolescence due to excess operating costs.
3. Obsolescence due to low environmental friendliness, ergonomics, etc.
Technological wear - this is wear caused by differences in the design and composition of structural materials used in analogue objects compared to the object being evaluated, as well as a change in the technological cycle of production in which the object being evaluated is included.
Thus, technological depreciation, in contrast to moral depreciation, makes the equipment in question unnecessary, in principle, within the framework of a new technology.
It should also be noted that, unlike moral depreciation, technological depreciation can only be determined by experts and, therefore, approximately.
External wear and tear (economic obsolescence)- depreciation of property due to the influence of external factors, namely: a change in optimal use, legislative changes, a change in the balance of supply and demand, deterioration in the quality of raw materials, the qualifications of the workforce, etc.
Economic obsolescence is almost always considered unrecoverable, since the potential cost of eliminating the external elements that caused this obsolescence always, with rare exceptions, exceeds the value added to the property.
Since economic obsolescence is the result of external influence that affects the enterprise as a whole, and not on each object separately or their group, economic obsolescence is more often considered when applying the income approach.
Among the causes of economic obsolescence are the following:
a reduction in demand;
increased competition;
· Changes in the structure of stocks of raw materials;
Growth in prices for raw materials, labor or utilities without a corresponding increase in the price of manufactured products;
· inflation;
high interest rates;
legal restrictions;
changes in the structure of the goods market;
environmental factors.
When calculating the value of economic obsolescence, the principle of substitution is used, i.e. take into account the usefulness of the object. Due to economic reasons, part of the equipment (investments, capacities, etc.) is not used and does not bring any benefit. And since the utility of an object due to underutilization is less than that of an object operating at full capacity, its cost also decreases.
The underutilization, and the resulting loss of value, is expressed by the equation:
where k e is the coefficient of economic obsolescence;
N p - real power or nominal capacity of the object;
N n - rated power or rated performance of the object;
n is the drag coefficient, the Chilton coefficient, reflecting the influence of the law of economies of scale.
Underutilization can cause functional obsolescence, and sometimes physical deterioration of equipment.
Since any object can be subjected to different types of wear at the same time, the accumulated wear is taken into account in the assessment.
Accumulated depreciation the object of appraisal is defined as the sum of value losses under the influence of all obsolescence (wear and tear) factors.
Functional and economic depreciation is more often taken into account indirectly, through the prices of analogous objects, while physical depreciation should be taken into account directly, since it is specific to each object of assessment.
Option 9
Topic: Depreciation of equipment at the enterprise and justification of ways to reduce it.
Introduction 3
1. Concept, types, indicators of equipment wear and value
its decline. 5
2. Analysis of equipment wear at the enterprise. 13
3. Ways to reduce equipment wear. 23
Conclusion 28
List of used literary sources 29
Introduction
The main production assets, consisting of buildings, structures, equipment involved in the production process, are the basis of the activity of any enterprise. It is the provision of fixed assets in the required quantity and their rational use that are the most important factors in increasing the efficiency of production. Today, in the Republic of Belarus, this increase is provided not by increasing the number of fixed assets, but due to their more efficient use.
Rational and economical use of fixed assets is the priority task of the enterprise. It is necessary to form a system for maintaining machinery and equipment in working order, which includes maintenance and repair.
In order to rationally and economically use fixed assets, it is necessary to conduct an economic analysis. With its help, tactics for the development of the enterprise are developed, reserves for improving work are identified, and performance results are evaluated.
In order for the enterprise to function normally, it is necessary to have funds and sources. In a market economy, this is due to the expansion of production volume. At the same time, special attention is paid to the growth and improvement of fixed assets, primarily equipment. For the efficient operation of the enterprise, it is necessary to take into account the wear and tear of equipment and look for ways to reduce it.
So, the purpose of this course work is to study the wear and tear of equipment at the enterprise and justify ways to reduce it.
Objectives of the course work:
1. To study the concept, types, indicators of equipment wear and the significance of its reduction.
2. Analyze the wear and tear of equipment at the enterprise.
3. Substantiate ways to reduce equipment wear.
1. The concept, types, indicators of equipment wear and the significance of its reduction.
A significant share of the costs of the enterprise - the costs associated with the use of machinery, equipment, production facilities. Their use has a characteristic feature: unlike material resources, they are not consumed in one production cycle. Capital resources last for years and wear out.
Depreciation of equipment is the loss of its value and performance. Wear and tear can occur due to many reasons: aging of equipment, loss of its competitiveness, etc. Today, the fight against wear and the extension of the service life of equipment is a very urgent task.
Depreciation in the economic sense means the loss of value of the equipment during its operation. In this case, two types of wear are distinguished: physical and moral. Physical wear and tear occurs due to equipment aging and loss of its performance, and moral wear due to loss of competitiveness.
Physical depreciation is the loss of fixed assets of their original consumer value, as a result of which they become unusable and require replacement with new funds. This is normal wear and tear. It is the result of past periods of operation, environmental influences and downtime. As a result of physical wear, the technical characteristics of the object worsen, the probability of breakdowns and accidents increases, the residual service life of the object as a whole or some of its components and parts decreases. This leads to an increase in waste, the risk of serious accidents, the inability of machines and equipment to meet the requirements for proper functioning. Production costs (materials, energy), maintenance and repair costs also increase.
The physical type of wear is divided into subspecies:
1. For the reason that caused the wear, wear of the first and second kind is distinguished. Depreciation of the first kind accumulates as a result of operation. Depreciation of the second kind occurs due to accidents, natural disasters, violations of operating standards, etc.
2. According to the flow time, wear is divided into continuous and emergency. Continuous is a gradual decrease in the technical and economic indicators of objects. Emergency - wear, flowing quickly over time.
3. According to the degree and nature of the distribution, wear can be global and local. Global - wear, uniformly spreading over the entire object. Local - wear that affects individual parts and components of the object.
4. According to the depth of flow, partial and complete wear are distinguished. Partial - depreciation, allowing repair and restoration of the object. Full involves the replacement of this object with another.
5. If it is possible to restore the lost consumer properties, wear can be removable and irreparable.
6. According to the form of manifestation, technical and structural wear are distinguished. Structural wear is manifested in the deterioration of the protective properties of external coatings and the increase in fatigue of the main parts and components of equipment, which increase the likelihood of accidents. Technical wear and tear is wear and tear, expressed in a decrease in the actual values of technical and economic parameters compared to standard or passport values.
To assess the degree of physical wear and tear, the following assessment methods are used:
Expert method based on the examination of the actual technical condition of the object;
Lifetime analysis method based on comparison of actual and standard life of equipment.
Methods for calculating physical wear:
1. The effective life is based on the assumption of the reliability of determining the remaining life of the object (T ref). Calculated according to the formula:
T eff \u003d T n - T ost, where T n is the standard life.
Physical wear F and is determined by the following formula:
F i \u003d T eff / T n
2. Expert analysis. The following table is used to evaluate wear:
| Physical deterioration, % | Technical condition assessment | General characteristics of the technical condition |
| 0-20 | Good | There are no damages or deformations. There are individual malfunctions that do not affect the operation of the facility as a whole and can be eliminated during the current repair |
| 21-40 | Satisfactory | The facility is generally suitable for operation, however, it requires repair already at this stage of operation. |
| 41-60 | unsatisfactory | The operation of the facility is possible only if repairs are carried out. |
| 61-80 | emergency | The state of the object is emergency. The performance of its functions is possible only when carrying out repair work or complete replacement of individual components and parts. |
| 81-100 | Unsuitable | The facility is in an unusable condition. |
3. Profit loss method (economic-statistical method).
Physical wear F and is calculated by the formula:
F i \u003d (P o -P t) / P o, where P o - profit from the new object, P t - profit from the object in the current state.
The values of P o and P t must be defined for the period (for example, month, quarter).
4. Loss of productivity method (economic-statistical method)
Ф i = ((Q o – Q t)/Q o) n , where Q o is the performance of the new object (passport characteristic), Q t is the performance of the object at the time of evaluation, n is the Chilton braking coefficient. For objects of the machine-building industry, it averages 0.6-0.7.
5. The method of the stage of the repair cycle.
This method is based on the assumption that the decrease in consumer properties of machinery and equipment during operation linearly depends on the operating time. At the same time, it is assumed that the repair carried out returns part of the consumer properties.
At the end of the repair cycle, that is, before the first overhaul, the value of the consumer properties of the PS p is calculated by the formula:
PS p = PS - K p * PS, where PS are the consumer properties of the new object, K p is the relative decrease in consumer properties to the end of the repair cycle.
Accounting for the increase in consumer properties due to major repairs is carried out according to the formula:
PS r = PS –K r * PS + DPS, where DPS is an increase in consumer properties due to a major overhaul.
The calculation of physical wear (F and) is as follows:
Ф i \u003d (Ps o -PS t) / Ps o,
PS t \u003d PS - t * dPS,
t \u003d M * D * K cm * K vi * T s,
dPS \u003d (PS o - K r * PS + DPS) / T r, where
Ps o - the value of consumer properties at the beginning of the repair cycle,
t - operating time after overhaul,
M is the number of months worked after the overhaul,
D is the number of working days in a month,
K cm - shift coefficient,
K wi - coefficient of intra-shift use,
T s is the duration of the shift.
6. Method of element-by-element calculation.
When calculating wear using the element-by-element calculation method, it is necessary to represent the object in the form of several basic elements. Depreciation is determined for each element separately and is taken into account taking into account the share in the cost of the entire object. The wear calculation scheme is described by the formula:
F ip = f i *(c i /c S)*(T i /T S), where f i is the actual physical wear of the i-th element, c i is the cost of the i-th element, c S is the cost of the object as a whole, T i is the standard the service life of the i-th element, T S - the standard service life of the object as a whole.
The decrease in the value of capital goods may be associated not only with the loss of their consumer qualities. In such cases, we speak of obsolescence.