MATHEMATICAL MODEL OF FORECASTING AND DEFINITION OF THE SIZE OF SPARE PARTS FOR AUTOMOTIVE SERVICE STATIONS WITH CONSIDERATION OF LOSS OF SALES


ABSTRACT

Khavruk V.O. Mathematical model of forecasting and definition of the size of spare parts for automotive service stations with consideration of loss of sales. Visnyk National Transport University. Series « Economic sciences». Scientific and Technical Collection. - Kyiv: National Transport University, 2020. - Issue 2 (47).

The article deals with the order of formation of the mathematical model of forecasting and determination of the volume of spare parts, taking into account lost sales on the basis of actual expenses for repairs and sales through trade

Object of research - system of inventory management of car maintenance stations

Purpose of the study - to carry out research of mathematical model of forecasting and determination of spare parts volume taking into account lost sales and to find out the main components of it.

Method of the study - the analysis and formalization: quantitative indicators of automobile parts reserves, methods of forming components and parameters of a mathematical model.

It is established that the methodology of constructing a mathematical model involves the formalization of the main processes of the cost of automotive spare parts. The mathematical model includes the costs of spare parts: 1) for repairs of cars; 2) through the sale of a spare part in a shop operating at a service station.

It was found out that in order to take into account the lost sales of spare parts, it is necessary to clearly register customer inquiries, indicating the factory catalogs of spare parts numbers, their number. In this case, in case of the need for a spare part and its presence in the warehouse of the enterprise, the client refuses to purchase, then such a requirement is not taken into account as dissatisfied.

The construction of a mathematical multiplicative model of prediction and determination of the amount of spare parts based on lost sales in which the value of the seasonal component is not a constant, but represents a certain proportion of the trend value.

The formulas for determining the need for spare parts in a multiplicative model based on parabolic, linear trends of demand and seasonal variation are considered and given.

The importance of the seasonal component in the mathematical model of forecasting is substantiated; it is a factor of forecasting error, it allows to find out the causes of fluctuations and to calculate the insurance stock of parts. To calculate the seasonal component, a method of correction of the trend equation with an asymmetric seasonal wave is presented.

The results of the article can be used to increase the efficiency of inventory management at both technical maintenance stations of cars and any subjects of entrepreneurial activity, in the case when there is a problem of dissatisfied consumer demand.

Forecast assumptions about the object of study - the specification of the model for determining the volume of spare parts by studying the seasonal fluctuations in demand and studying the main trends in the development of car service services and the existing model range of cars, their age composition.

KEYWORDS: DETAIL, SPARE PARTS, PROBABILITY, QUANTITY, MODEL, VOLUME, PERIOD, DEMAND, NEED, FORECAST, SALE, IMPLEMENTATION, EQUATION, SERIES, SEASONAL VARIATION, TREND.

REFERENCES

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AUTHOR

Khavruk Volodymyr, National Transport University, assistant to chair of technical operation of cars and autoservice, e-mail: khavruk@gmail.com, тек+380950187190, Ukraine, 01010, Kyiv, Omelianovycha- Pavlenka str. 1, of. 410.

REVIEWER

Brehida Fedir, Candidate of Science (Engineering), DP «DERGAUTOTRANSNDIPROJECT», Head of Department of research and is standard-legal maintenance in sphere of technical operation of road vehicles, e-mail: to@insat.org.ua, тек+380442010806, Ukraine, 03113, Kyiv, pr. Peremogy 57, of. 714.

Bondarenko Yevhen, Ph.D., Economics (Dr.), professor, National Transport University, department of economics, Kyiv, e-mail: kaf-ekonomika_ntu@bigmir.net, tel.+380442803016, Ukraine, 01010, Kyiv, Omelianovycha-Pavlenka str. 1, of. 313.

Article language: Ukrainian

Open Access: http://publications.ntu.edu.ua/visnyk/47/173.pdf

Print date: 15.04.2020

Online publication date: 27.10.2020


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