Transport and logistics service of foreign trade cargo flows in integrated production systems

. The work describes the conditions of functioning of integrated service and logistics formations, taking into account the performance of consolidating operations in transport hubs. A methodology for optimizing structural indicators in transport and service systems is proposed based on the condition of the creation of combined consignments of international cargo. There is a well-founded possibility of applying the principles of comprehensive evaluation of the results of service of foreign trade cargo flows to increase the competitiveness of the transport and logistics service. Using the basic principles of probability theory and mathematical statistics, the random nature of cargo flow service is modeled, and a methodology for substantiating the numerical values of the main indicators of the production activity of integrated formations is proposed under the condition of the random nature of the demand for transport and logistics services. According to the results of the calculations, the main indicators of service and logistics maintenance of foreign trade cargo flows in consolidating nodes were determined under the condition of the stochastic nature of transport and technological processes. The interpretation of the performed calculations provides grounds to propose a set of measures to improve the infrastructure support of integrated production formations. And the structural optimization of transport and service systems of international direction allows ensuring a competitive level of reliability of transport and logistics service of foreign trade cargo flows.


Formulation of the problem
The sustainable development of international trade relations between individual countries is based on the principles of global economic integration.With the specified conditions, improving the economic indicators of individual economic structures requires the introduction into everyday practice of their systemic interaction within the agreed transport and technological processes [1].Comprehensive studies of the efficiency of international transport and service systems testify to the need to improve infrastructure support for integrated processes.In the mentioned production formations, the optimization of infrastructure characteristics is the basis of the development of organizational and structural foundations for improving the operation of transport and logistics systems [2].Therefore, increasing the competitiveness of the transport and logistics service in servicing foreign trade cargo flows should be based on taking into account a large set of influencing factors in the system.[3].
In these circumstances, an important and necessary condition for increasing the competitiveness of integrated production processes in production entities of an international orientation should be the justification and creation of an optimal structure of transport and service systems [4].Service-logistics connections in the specified production formations, including loadgenerating, load-consolidating and load-absorbing arrays, are considered as influencing factors in a single transport-technological process formed from individual components of the system [5].Effective production activity of transport nodes is ensured by achieving a certain level of reliability of cargo flow maintenance, provided that the existing level of infrastructure support is used [6].Therefore, the organizational structure of such a system must simultaneously meet both the competitive level of technical and operational indicators, and the reliability of service and logistics of foreign trade cargo flows in transport-consolidating nodes [7].
The use of criteria for the optimization of transport and logistics costs when servicing a consolidated batch of import-export and transit cargo flows involves mathematical modeling of transport and service processes under the condition of the random nature of technological and technical-operational indicators [8].In the specified production structures, the theoretical basis for conducting complex calculations should be the substantiation of the numerical values of the influencing factors of the transport and service system in the stochastic process [9].Modeling of service and logistics maintenance of the production process should take into account the functional features of infrastructure components in production structures [10].And the application of the proposed methodology of integrated assessment of freight flow service allows forming a complex of measures for structural optimization of transport and service systems of international direction [11].

Methodology for optimization of structural indicators in transport and service systems
A thorough analysis of the production interaction of individual components in the integrated system testifies to the random nature of independent transport and technological processes [12].The structure of such a transport and service system should take into account the stochastic nature of technological indicators.
A necessary condition for ensuring the reliability of the provision of service and logistics services in competitive international production systems is the integration process of creating a consolidated batch of foreign trade goods in transport hubs.The preaccumulation of a combined batch of export or transit goods followed by the use of high-performance loading mechanisms has a significant impact on the reduction of ship service times in sea trade ports.The implementation of the specified cargo consolidation operations has a significant impact on both the increase in the balance sheet value of the main production assets and the amount of working capital, as well as on the improvement of technical, operational and economic indicators of transport and logistics systems.
In the practical activity of production structures, the achievement of a certain level of reliability of service аnd in everyday production conditions, it is often necessary to provide a wide range of commercial services and to change the volume and structure of cargo flows throughout the entire service cycle [13].Therefore, the results of the impact of the specified features of the transport and technological process are characterized by the random value of the resulting indicators of the system's functioning [14].
At the same time, the need for timely fulfillment of contractual obligations to customers of transport and logistics services requires integrated production structures to comply with the specified deadlines for the performance of contracted service and logistics operations.In addition, the need to ensure certain reliability of the provision of such services should not affect the competitiveness of the production entity itself.That is, the organizational structure of such an integrated formation must be adapted to the stochastic nature of influencing factors.
From such circumstances, in order to maintain the necessary competitiveness of transport and logistics service of foreign trade cargo flows, there is a need to create transport and service systems of international direction with an optimal organizational structure.On the example of functioning in the transport hub of production structures for service and logistics of export cargoes, the methodology for the formation of such systems is presented in fig. 1. and logistics service is achieved by the use of a wide range of designs of service mechanisms.In addition, compliance with the established terms of service and logistics maintenance of foreign trade cargo flows in transport hubs, or the use of new technologies of the consolidating process requires both changes in the organizational structure of integration systems and adjustments to the infrastructure support of individual production formations.
The operational response of the integrated system to the influence of random factors consists in the modernization of the organizational structure of the production formation and the creation of new internal connections of the improved integration process.In addition, the unification of the transport and logistics infrastructure in a wide range of service technologies is of great importance in the process of prompt response of the system to the influence of external factors.

Random nature of transport and technological processes in integrated systems of international direction
The need to ensure a competitive level of reliability of service and logistics operations in production processes Organizational structure of transport and service systems in transport hubs for the creation of consolidated batches of foreign trade goods Operational and organizational and structural management of transport and logistics processes in integrated production structures

Service and logistics maintenance of foreign trade cargo flows in conditions of stochastic nature of transport and technological processes
Methodology for improving the competitiveness of integrated production structures involves increasing the reliability of transport and terminal service, provided that the production indicators meet the specified criteria.The set goal requires system interaction and coordinated cooperation from service entities in the conditions of both the stable operation of service and logistics formations and the stochastic nature of transport and technological processes.Under such circumstances, the solution to the practical problems of the specified direction consists in optimizing the structure of transport and service systems in the conditions of the stochastic nature of service processes.
In production structures of an international orientation, when creating a consolidated batch of foreign trade cargoes, economic indicators are usually used as a criterion of competitiveness.To evaluate the results of system activity of integrated production formations, the total transport and service costs in the system can be accepted as optimization indicators using the number of n vehicles as a control variable Numerical values of random values of hourly productivity Pk (р) and hourly costs Sk (р) of a separate station in a transport hub are determined by the reliability of terminal service in the system.The cost of transporting a ton Sm (р) of a consolidated batch of exportimport cargo by cars with a carrying capacity q is characterized by the reliability of transport service.And the costs associated with downtimes of service stations Сk (р) and road vehicles Са (р) , respectively, are interpreted as interrelated values in the system.
Each component of the logistics cycle in the transport and service process has its own probabilistic characteristics, and their sum is characterized by a normal distribution.In the case of the stochastic nature of such a transport and service process, the probability of timely execution of individual X operations is determined as where Φ (…) is a tabular function of the standard normal distribution.
In this case, the reliability of transport and terminal service of foreign trade cargo flows, as a probability value in the interval (β1 ... β2), is determined by the dependence Using the theoretical prerequisites outlined, it became possible to determine the main transport and technological parameters and the resulting indicators of integrated production systems.For this purpose, on the example of the creation of a consolidated export batch of grain cargoes in the transport terminal, the total transport and service costs for servicing one ton of the specified cargoes B(n) and the optimal number of rolling stock in the system were calculated.As a random variable, the performance of the unloading mechanism in the system with two m = 2 service posts is characterized by the coefficient of variation υPk = 30%.Transport support of the system was carried out by heavy-duty road trains with a carrying capacity of q = 22 tons (table 1).

Pk, ton/hour
Reliability of transport service р(Pk) = 0,50 р(Pk) = 0,65 р(Pk) = 0,80 р(Pk) = 0,95 nopt, unit The specified situation is explained by the reduction of non-productive stoppages of road trains at service points, and accordingly, the reduction of the turnover time of the rolling stock on the route, the increase in productivity and the reduction in the total costs of the transport component.
At the same time, the increase in reliability indicators p(Pk) of terminal service leads to both an increase in service and logistics costs B(n) in the system and a decrease in the optimal number of road trains n in the transport and service system.For example, an increase in the reliability index of terminal service within the range of p(Pk) = 0,50...0,95 in the case of the productivity of service mechanisms Pk = 20 tons/hour leads to an increase in service and logistics costs by 4,6% (from B(n) = 11,50 €/ton for p(Pk) = 0,50 to B(n) = 12,03 €/ton for p(Pk) = 0,95).And the optimal number of nopt road vehicles for the numerical value of productivity Pk = 180 tons/hour under the same production conditions decreases by 43,6% (from nopt = 55 units for p(Pk) = 0,50 to nopt = 31 units for p(Pk) = 0,95).
The mentioned tendency of the change of the resulting indicators is explained by the fact that with increasing indicators of the reliability of terminal service p(Pk) using the mathematical dependence (3), numerical values β1 of the hourly productivity of a separate post are used in the calculations.In this case, when p(Pk) ≥ 0,50, the numerical value of productivity is less than the mathematical expectation of mPk of the specified parameter.And the value of the variable components of the mathematical dependence (1) has a significant influence on the reduction of the optimal value of nopt in the system.
The second important factor in the stochastic servicelogistics process is the duration of terminal service of foreign trade cargo flows.The specified operation includes the entire range of technological and logistic services in transport hubs: weighing of road vehicles, documentation of goods, non-production downtime while waiting for service, etc.
Under these circumstances, in the transport and service system with two service posts m = 2 of the design productivity Pk = 120 ton/hour each, the hourly productivity of Phour and the hourly profit of Ghour were calculated on the condition that motor vehicles of different load capacities are involved in the system.The results of the influence of the average duration of terminal service tterm = 1,5 hour as a random variable with a coefficient of variation υtterm = 35% are presented in тable 2. The performed calculations confirm the previous thesis about the expediency of equipping transport and service systems with heavy-duty vehicles and road trains.For example, an increase in the carrying capacity of road vehicles in the range of q = 10...22 tons leads to an increase in the hourly productivity indicator by 2,13 times (from Phour = 2,63 ton/hour for q = 10 ton to Phour = 5,62 ton /hour for q = 22 ton) provided p(tterm) = 0,50 and 2,15 times (from Phour = 2,14 ton/hour for q = 10 ton to Phour = 4,59 ton/hour for q = 22 tons) under the condition of reliability of terminal service p(tterm) = 0,95.The indicator of the hourly profit of Ghour in the specified conditions increases by 4,15 times, respectively (from Ghour = 6,54 €/hour for q = 10 ton to Ghour = 27,18 €/hour for q = 22 ton) under the condition of p(tterm) = 0,50 and 4,19 times (from Ghour = 5,31 €/hour for q = 10 ton to Ghour = 22,24 Ghour for q = 22 ton) for the reliability indicator of terminal service p(tterm) = 0,95.
At the same time, as the previous comment shows, the increase in the reliability of service and logistics service in the transport and service terminal slightly worsens the resulting indicators of Phour and Ghour in the system.For cars with a carrying capacity of q = 10 tons, an increase in the reliability indicator p(tterm) of terminal service within the range of p(tterm) = 0,50...0,95 leads to a decrease in the Phour indicator from 18,6% (with Phour = 5,62 ton/hour for q = 10 ton to Phour = 4,59 ton/hour for road trains q = 22 ton).In similar conditions, the decrease in the hourly profit of Ghour is 18,8% for the carrying capacity indicator q = 10 tons and 18,2% for the value q = 22 tons, respectively.
By analogy with the previous influencing factor, the increase in the numerical value of the reliability of terminal service p(tterm) requires taking into account the increased range of values of the tterm indicator in the system.As a result, the well-known thesis that increasing the reliability of system functioning requires either additional financial costs or the use of system material and financial resources is confirmed.

Ensuring a competitive level of reliability of transport and terminal service of export cargo flows
The conducted analysis of the peculiarities of service and logistics activities of integrated production formations allows determining trends and the nature of changes in the resulting indicators.And with the help of the obtained results, it becomes possible to substantiate the directions of structural optimization of transport and service systems of an international direction.
The peculiarity of the transport and terminal service of foreign trade cargo flows in sea trade ports is the great demand of participants in the transportation process for the performance of consolidating and service operations and the limitation of the number and capacity of warehouses in places of direct transshipment.In most cases, proven production practice in such processes is the preliminary accumulation of products purchased from manufacturers ready for export in specialized warehouses at a relatively short distance from the consolidating node.
For this purpose, the work of transport hubs for the consolidation of export grain cargo flows and the justification of the choice of technology for the maintenance of sea merchant ships were modeled in the work.Typical transport and technological processes of servicing foreign trade cargo flows in sea trade ports are presented in the table 3.That is why one of the important components of the transport and terminal service of foreign trade cargo flows in integrated formations should be the structural optimization of motor vehicle support.
The numerical value of the daily productivity Pday of the transport enterprise for the defined levels of reliability of transport and terminal service is highly correlated with the indicators of the optimal number of nopt road vehicles and the hourly productivity Phour of an individual vehicle.In the situation of infrastructural support of the transport and service system with road trains with a carrying capacity of q = 22 tons for the transportation of grain cargoes over an average distance of lm = 50 km, the change in daily productivity ∆Pday for technological scheme №1 occurs within the range of %Pday = 8,3% under the condition of the initial level indicator p(tterm) = 0,65 to %Pday = 25,0% with a high In the specified circumstances, taking into account the significant volumes of export transportation during the term defined by the contract terms, the integrated process involves the involvement of a significant number of road vehicles.
A detailed analysis of literary sources and the use of previous calculations allow differentiating separate levels of reliability p(X) of transport and terminal service of foreign trade cargo flows in separate service and logistics processes of X: • basic p(X) = 0,50; • initial p(X) = 0,65; • average p(X) = 0,80; • high p(X) = 0,95.With the use of the developed mathematical models based on the results of the calculations, it became possible to determine the calculation parameters and the resulting indicators of the transport service (table 4):  ∆Phour -daily change in the productivity of the motor vehicle enterprise in connection with the increase in the level of reliability of transport service in the system;  ∆B(n) -change in total transport and service costs in the system, as a result of increasing the reliability of terminal service;  ∆Ghour -a change in the daily profit of a motor vehicle company when the level of terminal service is increased in the absence of additional infrastructure support;  ∆Gcons -change in total profit in the specified transport and technological process for a consolidated batch of cargo.
level of reliability p(tterm) = 0,95 of transport and terminal service.For technological scheme №4 under the specified conditions, ∆Pday indicators change from %Pday = 5,6% under the condition p(tterm) = 0,65 to %Pday = 12,2% under the condition of reliability of transport and terminal service p(tterm) = 0,95.The decrease in the rate of growth of ∆Pday of the daily productivity of the enterprise with an increase in the ship consignment of cargo is explained by a greater number of nopt vehicles involved, a more stable operation of the transport and service system, and therefore a much smaller impact of non-production stoppages of road vehicles on the numerical values of Pday productivity indicators.At the same time, increasing the level of service reliability p(tterm) in production structures by increasing the number of road trains leads to an increase in costs ∆B(n) in the system.Considering the specificity of the theoretical distribution of the random variable B(n), the increase in costs ∆B(n) between the basic (p(tterm) = 0,50) and the initial (p(tterm) = 0,65) and the basic (p(tterm) = 0,50) and average (p(tterm) = 0,80) reliability levels differ by 2,16 times.Under the same conditions, the growth rate of ∆B(n) for the following levels: «average -high» compared to the previous «initial -average» is 3,62 times.The noted unevenness is explained by the acceleration of the number of requests in the queue for service, which indicates the «saturation» of the production formation with road vehicles.
As a result, the increase in the level of service reliability of consolidating cargo flows is the reason for the reduction of the total ∆Gcons profit in the system.The numerical value of the decrease in the ∆Gcons indicator is, on the example of technological scheme №1, within the range of 55,9% for the initial level (p(tterm) = 0,65) to 57,3% for the high level (p(tterm) = 0,95) service reliability from the growth of ∆B(n) costs.The obtained results indicate the presence of additional income for the services provided in the system in the event of an increase in service reliability.

Conclusions
The methodology of the optimization process for production structures in integrated formations is given in the completed work.The conducted studies of the functioning of service and logistics systems in consolidation nodes take into account the stochastic nature of transport and technological processes of an international direction.
The generalization of multivariate calculations of the resulting indicators indicates the expediency of equipping production structures with large-tonnage cars and road trains.The specified direction allows minimizing the total transport and logistics costs, thereby increasing the competitiveness of such integrated formations.
Increasing the level of reliability of transport and terminal service in consolidation nodes increases the stability of service and logistics systems, as well as significantly improves the reputational attractiveness of the specified production structures.At the same time, achieving the specified results requires additional involvement in the system of material and financial resources, which is reflected in the final results of production formations.
One of the directions of optimization of the structure of transport and service systems should be the inclusion of additional infrastructure elements for the preliminary consolidation of cargo or changes in the throughput of such a system.And future research in such a scientific direction should provide an answer to the question of establishing an economically justified balance between the level of reliability of transport and terminal service and the competitiveness of production structures.

Fig. 1 .
Fig.1.Methodology for optimization of technological indicators in the structure of international transport and service systems Source: compiled by the authors based on[3] nopt, unit B(n), €/ton The performed calculations confirm the well-known facts that the increase in productivity Pk of service mechanisms contributes to the reduction of total costs ∆B(n) for different values of p(Pk) of service reliability.So, under the condition of the average distance of delivery of consolidating goods lm = 50 km occurs within ∆B(n) = 5,0% (from B(n) = 11,50 €/ton for Pk = 20 ton/hour to B(n) = 10,93 €/ton for Pk = 180 ton/hour) for p(Pk) = 0,50 to ∆B(n) = 7,9% (with B(n) = 12,03 €/ton for Pk = 20 ton/hour to B(n) = 11,08 €/ton for Pk = 180 ton/hour) for p(Pk) = 0,95.

Table 1 .
Changes in costs in integrated production structures due to changes in the level of reliability of transport services in transport hub [compiled by the authors].

Table 2 .
Changes in costs in integrated production structures due to changes in the level of reliability of terminal service in transport hubs [compiled by the authors].

Table 3 .
Typical transport and technological processes in sea trade ports with export and transit grain cargoes.

Table 4 .
Dependence of the resulting indicators of the transport and service system on the reliability of transport and terminal service [compiled by the authors].