Rare demand is an important part of the inventory management, nevertheless there are no any appropriate analytical descriptions or numerical examples of it except separate papers where considered the possibility to describe rare demand with Poisson distribution. The divergence between forecasts and actual data could be explained by the following reasons: the first one—extreme values in preforecasting period, as well as not significant ‘length’ of the analyzed time period; the second one—taking data for the forecast from the period of conduction certain actions (sales, promo, etc.), consideration of these actions might be done with combined forecasting methods. The paper describes the approach to assessment of inventory consumption for rare demand based on Poisson distribution. Besides, the paper contains the numerical examples and analysis of the results.
To date, a diverse array of expert assessments for quantitative (tangible) and qualitative (intangible) objects based on the analytic hierarchy process (AHP) has been accumulated in various fields of knowledge. The systematization and analysis of the collected data made it possible to put forward the hypothesis that some of the indicators (the eigenvalue of the matrix, the consistency index, and the ration of consistency) can be considered in the form of aggregates of random variables representing an intellectual product and reflecting features of human thinking. The systematization and statistical processing of the results obtained by experts on the basis of the AHP showed that the distribution functions of the values of expert estimates for the consistency indices significantly differ from the similar functions of the generated matrices.
The carried out studies show that from the point of view of the issue of efficiency increase of logistical systems, there are several key aspects. Firstly, choice of methods for managing the triad of logistics functions ‘inventory management - warehousing – transportation’, where the inventory management issues are considered as the most relevant ones. Secondly, there is recognized the need to move the studies of multi-level systems within the framework of the concept of supply chain management. Nowadays, supply chains, which are represented by the distribution system, are widespread in practice. The most common of them are two-level ones with a central supplier at the second level and a certain number of companies at the first level; and multi-level systems of the distribution configuration network in which multi-nomenclature stocks are located. The article is devoted to the design and enhancement of analytical platform for inventory management in such distribution systems.
Transportation is a key logistics function, which determines the dynamic nature of material flows in logistics systems. At the same time, transportation is a source of uncertainty of logistics operations performance in the supply chain.Obviously, the development of a new approach for evaluation of the duration of delivery “Just-In-Time” (JIT) will improve the efficiency of supply chains in accordance with one of the major criteria, namely customer satisfaction. One of the basic approaches to make effective management decisions in transportation and other logistic operations is the JIT concept. In the majority of examined sources the JIT concept is described on the verbal level without any usage of calculation dependences. The paper is devoted to the formation of analytical and simulation models, which allow obtaining the probabilistic evaluation of the implementation of unimodal and multimodal international transportation JIT. The first model where the order of the operations implementation does not affect final result is formed on the basis of the probability theory: distribution laws composition, theorems of numerical characteristics of random variables, formula of complete probability. The second model accounts the impact of operations implementation order in transportation and their interconnection and is based on the simulation (the method of statistic experiments) and shown as a corresponding algorithm, which allows to consider different limitations (technical, organizational and so on). Considered analytical dependences give the possibility to obtain the necessary estimations of the transport operations implementation according to JIT: mean transportation time, delivery implementation probability by the set moment or the delivery time with the set probability. To carry out some comparative calculations and clarify the algorithm, two international routes have been chosen: the first one is a unimodal road transportation, the second one is a multimodal transportation (road and marine transport). All the data, which is necessary for calculation has been collected on the basis of official information (in particular, the data of tachograph, special questionnaires filled in by the drivers, the survey results of the managers). For unimodal transportations analytical dependences and modelling results give close results. For the combined multimodal transportations taking into account various limitations the preference must be given to the simulation. The modelled indexes take into consideration their intercommunication and definitely estimate the supply chains reliability, and this allows decreasing the uncertainty of the logistic system.
The analysis of perspective directions of development of logistical integration allows to establish the importance of the
formation of mechanisms of management of integrated logistic functions, and also functional complexes. The
complexity of the problem is determined by the variability of the types of interaction between levels in the investigated
multi-level distributed systems, which in turn result in the variety of models of inventory management. They can be
divided into three main subgroups: the first is with independent processes, the second is with coordination and the
third – integrated models.
The most expedient way, in our opinion, to generalize the numerous AHP studies is by the formatting of a morphological
table and the corresponding block diagram. On the basis of the table, it is possible to take into account unobvious
variants that can be missed with a simple search. Thus, the AHP, despite its obvious benefits, requires further
research so as it can be successfully applied in the management of supply chains.
Success of any logistics enterprise in the context of digital economy progress directly depends on regular and effective innovations to the area of improving analytical applications and information systems in such actively developing fields of knowledge as strategic management, distribution networks development, and supply chain management. In an effort to ensure a sustainable economic circumstance under conditions of strong competition, the most perspective companies are increasingly focusing on the development and introduction of modern methods and tools for intelligent data analysis. The article focuses on the consideration of issues related to the use of modern simulation approaches and such components of the soft computing concept as neural networks, fuzzy logic and evolutionary computations in solving the problems of multifunctional logistics and supply chain management.
The structure of the applied theory of the logistics systems design and planning continues to evolve in the circumstances of supply chain integration. The synchronization of material, service, information, and intellectual flows offers new opportunities for cross-disciplinary analysis. The article considers the development of conceptual framework, as well tactical and operational levels (e.g. existing terms and definitions, economic indicators, methods and models) that are applied in the research on the creation of value nets in terms of their flexibility, speed and reliability.
The paper examines correlation in planning and organizing logistics of supplying goods and the issue of safety at urban roads; a model to determine the time of goods delivery is proposed on the basis of logistic concept “just-in-time” that takes into account the requirements of road safety on the one hand, and the customer-oriented approach of delivery, applied technologies and management solutions, on the other. The model is based on an integrated approach to the management of logistics processes; it can serve as a basis for decision making among departments in transport enterprises, logistics departments at industrial and trade enterprises, and corporate consumers. The paper also proposes to add the second level parameters to the system of logistics key performance indicators (KPI); these parameters would allow evaluating the target performance in goods transportation, as well as actual performance of logistics operations, including transportation in terms of road safety.
The article substantiates the concept of quantitative assessment of knowledge uncertainty in accident reconstruction tasks based on application of mathematical tools of the fuzzy set theory allowing considering an uncertainty of initial data caused for instance by varying resistance to the motion of investigated objects at the apex stages of the contact–separation processes. The application of the mathematical tools of the fuzzy set theory can substantially expand the potential of applying the methodology to the automobile and technical expertise and provide the enhancement of authenticity and improve the accuracy of making conclusions about the accident reconstruction results.
In this article we deal with the approach to logistic systems efficiency increase on the basis of various forms of logistic integration development in supply chains, with modified variants of model of economic order quantity for the echelon two-level systems which allow considering the costs correlations at the different system levels, the different stock warehousing strategies, the multi-nomenclature of orders. The appropriate calculations have been done for the suggested modified models approbation.
For efficiently increasing the logistic systems, the core specialists' attention has to be directed to reducing costs and increasing supply chains reliability. A decent attention to costs reduction has already been paid, so it can be stated that in this way there is a significant progress. But the problem of reliability evaluation is still insufficiently explored, particularly, in such an important sphere as inventory management at the dependent demand. In the article there is a suggested methodical approach that allows calculating the safety stock quantity at the dependent demand in view of supply chains reliability requirements; the variants for different inventory management strategies at the dependent demand are examined; optimal strategy choice algorithm and results of total costs calculation in view of the reliability are given.
In the article there is a suggested methodical approach that allows calculating the safety stock quantity at the dependent demand in view of supply chains reliability requirements; the variants for different inventory management strategies at the dependent demand are examined; results of total costs calculation in view of the reliability are given.
In this article we deal with the approach to logistic systems efficiency increase on the basis of various forms of logistic integration development in supply chains, with modified variants of model of economic order quantity for the echelon two-level systems.
For evaluating the integrated supply chains' (SCs) effective functioning, some new criteria are frequently used apart from the total logistics costs (TLC). These criteria characterise the quality and reliability of accomplishing logistics operations and functions. It is obvious that these metrics are connected and their separate representation is a consequence of not enough developed supply chains' theoretic model and, accordingly, analytical tools allowing carrying out a comprehensive assessment of these metrics. The paper presents the critical analysis of the existing approaches to the TLC evaluation and SC reliability, the methodical approach which allows evaluating the total costs indexes and supplying chains reliability. This approach includes, firstly, the equation of the total logistics costs; secondly, the reliability evaluation model of a simple supply chain which is a reserved system with a renewal; thirdly, a complex of models for the evaluation of the reliability of basic logistics operations (purchase, order processing, choice of intermediaries, transportation, warehouse placement and storage). As most indicators which describe the chain functioning are random values, to obtain the required evaluations there is a developed algorithm based on simulation.
There is no unambiguous answer to what is the driver for modern logistics. According to practicing logisticians, optimal solutions can be found only during the process of physical distribution. From the point of view of academic science, all optimization issues in logistics are determined at the stage of theoretical background and project design. Obviously, a more complex approach to solve the problem of increasing competitiveness by means of efficient supply chain management can be found only as a result of synergy between both theoretical research and practical experience. This statement is mostly applicable to a situation when the market is full of goods, and the need for optimizing procedures is recognized not only on the level of logistics, but on the level of all current operations in the national and world economy as well. The peculiarity of the modern stage of logistics development is in rapid IT implementation of all distribution processes, from the point of origin to the final consumer. This is due to increased manufacturing scale and world trading volume (which has exceeded 8% this year, according to WTO). Hereby it’s crucial to realize that behind each sophisticated software there is a whole complex of analytical models and methods. That is why to be competitive, enterprises should pay special attention to developing analytical approaches to face logistics business challenges.
Integrated supply chain management is becoming a promising direction of the research; its structure continues to evolve in conditions of integration and synchronization of material, service, information and intellectual flows, which in turn opens up new opportunities for interdisciplinary analysis. Unlike integrated logistics, where the main theoretical and methodological bases are already systematized, in the integrated management of supply chains (mainly, multi-level, called supply networks), this process only gets its development. Therefore, the article analyzes theories, methods, and models, economic metrics, existing terms, and definitions, taking into account the optimization of supply chains and the requirements for reliability, stability, and adaptability. An approach to the formation of integrated management of logistics systems based on the interrelation of the operational, tactical and strategic levels of decisionmaking is proposed. Information technologies, being a basis for supply chain planning, execution, and optimization systems, are recognized as the enabler for the proposed approach to the integrated supply chain management. With the help of IT, it becomes possible to unite the primary business processes throughout the whole chain, as well as using key performance indicators and operational information to identify bottlenecks in supply chains so as to provide their elimination in the most optimal way for the purpose of achieving critical strategies.