Publications

The ripple effect refers to structural dynamics and describes a downstream propagation of the downscaling in demand fulfilment in the supply chain (SC) as a result of a severe disruption. The bullwhip effect refers to operational dynamics and amplifies in the upstream direction as ordering oscillations. Being interested in uncovering if the ripple effect can be a driver of the bullwhip effect, we performed a simulation-based study to investigate the interrelations of the structural and operational dynamics in the SC. The results advance our knowledge about both ripple and bullwhip effects and reveal, for the first time, that the ripple effect can be a bullwhip-effect driver, while the latter can be launched by a severe disruption even in the downstream direction. The findings show that the ripple effect influences the bullwhip effect through backlog accumulation over the disruption time as a consequence of non-coordinated ordering and production planning policies. To cope with this effect, a contingent production-inventory control policy is proposed that provides results in favour of information coordination in SC disruption management to mitigate both ripple and bullwhip effects. The SC managers need to take into account the risk of bullwhip effect during the capacity disruption and recovery periods.

Separately, in the fourth chapter, the format of the problems of choosing the best solutions according to many criteria is considered in relation to the situation when it is necessary to take into account the uncertainty factor. For problems of this type, features and possibilities developed for the development of the theory of uncertainties in the analysis and decision-making in logistics are developed in theory. Namely, a possible specificity of the approach is noted, when the perception of the uncertainty factor is realized on the basis of the theory of fuzzy sets. In addition, the opportunity is presented for an appropriate decision analysis based on the classical approach, which involves the formalization and analysis of a full group of random events (in the format of a discrete case intervention model), the impact of which affects the final economic result. In relation to the indicated classical approach, which allows one to take into account the uncertainty factor, this chapter proposes a method that allows adapting multicriteria optimization procedures to such conditions. Of course, this is about optimizing solutions for logistics systems and related supply chains. This approach can be used when it is necessary to take into account the impact of random external factors on the final economic result, and for the probabilities of such random events the manager does not have reliable estimates that would allow the use of decision-making methods in risk conditions. To achieve this goal, a special format for using this approach in the form of an appropriate algorithm as applied to logistics research was formalized and developed for the first time. We are talking about a format that allows you to implement a synthesis of appropriate optimization procedures: 1) relating to the format of criteria developed in theory for choosing the best solutions for many criteria (we are talking about such criteria for choosing a direct type); 2) relating to the format of criteria developed in theory for choosing the best solutions in the face of uncertainty.

The article explores the problems of eliminating abnormal undesirable situations that arise when optimizing solutions according to many criteria in logistics research, which correlate with the phenomena of inadequate choice. For the task of multi-criteria route selection, problems of eliminating phenomena of this type are discussed and special procedures for identifying these phenomena are used. For the first time, a comparison is made of the effectiveness of eliminating the phenomena of inadequate choice based on the transition to generalized data and on the basis of a synthesis of the processes of the analytical hierarchy with the procedures of traditional selection criteria. It is shown that both approaches successfully eliminate the phenomenon of inconsistency in the nature of indicators of particular criteria. At the same time, it was proved that the transition to generalized data cannot guarantee the elimination of the phenomenon of inconsistency in the order of values ​​of particular criteria: the corresponding situations can nevertheless manifest themselves in an implicit form. An exception is the criterion of works, which effectively eliminates the phenomenon of inconsistency in the order of values ​​of particular criteria, both on the basis of a transition to generalized data and on the basis of a synthesis of the processes of the analytical hierarchy with traditional selection criteria

The sixth chapter presents the procedures for the possible filtering of alternatives that can be implemented on the basis of binary relations in logistics problems. Moreover, various special approaches to the implementation of such filtering are formalized. They are accordingly based on the so-called majority and minority principles for making such decisions. The presented filtering procedures of the analyzed alternatives make it possible to simplify the calculations when choosing solutions according to many criteria, make them more compact and reduce their implementation time in relation to real situations in practice, without compromising optimization goals.

The first chapter presents the specifics of optimizing solutions for many criteria in logistics and supply chain management. With regard to the format of such tasks, the possibility of exposure to undesirable phenomena of inadequate choice is revealed, and the possibilities of eliminating them using special approaches based on a synthesis of analytical hierarchy processes and selection procedures that are specially developed today for solving multi-criteria optimization problems are discussed.

The article discusses anomalous adverse events that occur when optimizing solutions according to many criteria in logistics research and called the phenomena of inadequate choice. The article explores relevant phenomena of inadequate choice, including the phenomenon of inconsistency in the directions of optimization; the phenomenon of inconsistency in the nature of indicators of particular criteria; the phenomenon of inconsistency in the presentation format for indicators of particular criteria; The phenomenon of inconsistency in the order of values ​​of estimates of particular criteria. For the phenomenon of inconsistency in the order of values ​​of estimates of particular criteria, the procedures for its identification for the minimax criterion, the ideal point criterion, and the product criterion are first formalized. It is shown for the first time that the manager’s attempt to translate in-kind indicators into cost indicators, although it can eliminate the phenomenon of inconsistency in the nature of indicators of particular criteria, but at the same time, it can explicitly give rise to a phenomenon of inconsistency in the order of values ​​of estimates of particular criteria. Numerical illustrations are given on the example of choosing a transportation route for many criteria, as well as for the model of multi-criteria distribution of goods in a warehouse network.

A new efficient algorithm for solving the linear separable problem of the synthesis of a communication network called the generalized method of potentials is considered and justified. It is a generalization of the known method of potentials for solving the standard transportation problem. The finiteness of the proposed algorithm is proved.

In this paper, we consider the problem of optimal resource allocation for the Gale problem of demand and supply in the presence of uncertain factors. Based on the Danzig-Wolfe decomposition method and the generalized potential method developed by the author earlier for the deterministic version of the problem, a numerical algorithm for solving the problem is constructed and justified

Collaboration and trust relationships are important success factors in supply chain management. However, in practice relationships between counterparties in supply chain face conflicts preventing from building ideal supply chain collaboration. This paper proposes a conceptual framework of agent-based model that helps to understand how individual behavior of counterparties in conflict situations and collaboration strategy effect on supply chain efficiency in dynamics. The research is based on Russian retail case study, describing a grocery sector where key market stakeholders are retailers and suppliers (manufacturers). The important feature of Russian grocery sector is a dominating power of retailers over suppliers. Author investigates the main drivers of conflicts in retailer-supplier’s relationships and offers a specification of agent-based model.

For the multiproduct EOQ-models the analysis of several vehicles deliveries feasibility factoring in vehicle capacity is conducted. It is proved that such deliveries with an increase in the number of vehicles that simultaneously used for a single delivery cannot be effective, if a discount is not given for the cost of such a delivery. The necessary and sufficient condition that sets the threshold level of the discount, at which the deliveries by several vehicles are able to compete with the traditional solutions, is established. The cases of numerical calculations are presented in the article.

We have performed a comparative analysis of the bio-oil produced by thermal liquefaction of microalgae in different solvents using high-resolution Orbitrap mass spectrometry and GC-MS approach. Water, methanol, ethanol, butanol, isopropanol, acetonitrile, toluene, and hexane were used as solvents in which the liquefaction was performed. It was observed that all resulting oils demonstrate a considerable degree of similarity. For all samples, compounds containing 1 and 2 nitrogen atoms dominated in the positive ESI spectra, while a relative contribution of other compounds was small. In negative ESI mode, compounds having 2 to 7 oxygens were observed. Statistical analysis revealed that products can be combined in two groups depending on the solvent used for the liquefaction. To the first group, we can attribute the products obtained by using protic (alcohols) and to the second by using aprotic (acetonitrile, toluene) solvents. Nevertheless, based on our results, we concluded that solvent possesses a minor impact on molecular composition of bio-oil. We suggested that the driving force of the liquefaction reaction is the thermal dehydration of the carbohydrate in algae, resulting in water formation, which could be the trigger of the producing of bio-oil. To prove this hypothesis, we performed the reaction with the dry algae in the absence of the solvent and observed the formation of bio-oil.

The purpose of this paper is to research multicriteria decision-making optimisation problems of logistics systems and supply chains considering conditions of uncertainty. The article presents an approach that allows adapting the procedures of multicriteria optimisation to the format of conditions of uncertainty. This approach is relevant for the situation when a manager does not have reliable estimates for the probability of random events and cannot use decision-making methods under risk conditions. The study proposes the synthesis of optimisation procedures, including the format of the multiple criteria decision-making theory and the format of procedures developed in the theory of decision-making in conditions of uncertainty. The specifics of this approach and algorithm for optimising such solutions are presented according to the inventory management problem.

Purpose

This paper aims to analyse the key trends in oil delivery and production and evaluate the capacities of crude oil transportation systems in the Western European region.

Design/methodology/approach

To meet these goals, qualitative data analysis was used to assess the contribution of countries in the region to the total crude oil production and delivery, the changes in concentration of crude oil deliveries and refineries’ capacities, the capabilities of the regional crude oil transportation system and the trends in crude oil supplies and processing from 2005 to 2015.

Findings

The study established that from 2013 to 2015 oil supply to the region’s refineries increased and generated additional stress on the transportation and refining infrastructure.

Research limitations/implications

This study examined the aggregate values of crude oil production, crude oil deliveries and refining capacities. In practice, different refineries are set to process certain types of crude oil. It is possible to use the described approach with a certain crude oil grade.

Practical implications

When developing the programmes for crude oil supply to refineries, it is vital to take into account the capacities of refineries and the capabilities of the crude oil transportation systems.

Originality/value

The study suggests that the region’s infrastructure has the necessary reserves to operate for the next few years without additional investments.

The paper contains the results of the study on the systematization and formalization of specialized approaches to planning supply chains of leading metal companies and comparison of these practices with the standard supply chain management models SCOR & CCOR & DCOR and GSCF. The paper defines the main directions of development of the methodology of supply chain planning in terms of its adaptation to the specifics of metals.

The paper contains the results of the study on the systematization and formalization of specialized approaches to planning supply chains of leading metal companies and comparison of these practices with the standard supply chain management models SCOR & CCOR & DCOR and GSCF. The paper defines the main directions of development of the methodology of supply chain planning in terms of its adaptation to the specifics of metals.

. In the article the logistics management and SCM organizational structures researchfindings that were conducted by the NRU HSE International Centre of Training in Logistics in 2014–2016 are considered. The sample of companies operating on Russian market accounted about 400 organizations. The form for the respondents of online survey was created. Each participant esti-mated the logistics management organizational structure (logistic and/or SCM department) individually. The assessment was conducted from the perspective of the correspondence between the organizational structure and corporate and logistics strategies, key business processes, organizational structure management efficiency, functional employees allocation and so on in the different aspects of supply chains and logistics controlling. The examples of typical logistics management structures of line and staff, matrix and project oriented structures are shown. Taking into consideration the importance of the SCM best practices and innovative technologies usage, the questions are highlighted in detail and a great variety of examples in SCM departments organizational planning are given.

The article presents the results of a study of changes in the regional labour market, resulting from the introduction of digital technologies, which are not only able to replace human labour, but also turn the means of access to information into the means of controlling physical processes. It is demonstrated, what social and economic risks in the structure of demand and supply are relevant to the transition to a new technological order in a region with high scientific and technical potential. The object of the research is the labour market of the St Petersburg agglomeration, numbering more than four million people, with a high proportion of intellectual migration. The purpose of the research is a qualitative and quantitative assessment of the structure of supply and demand in the regional labour market, as well as the formalization of changes occurring under the influence of digital technologies. In addition to traditional methods of statistical analysis and observation, in particular, the analysis of time series characterizing the dynamics of demand and supply of employees, asymmetric analytics of sectoral labour market transformations is used. The results of the study of the modification of the regional labour demand model are given, associated with the disaggregation of the organizational structures of companies, the emergence of parttime workers, the desire of high-tech businesses to reduce transaction costs, primarily labour costs. The directions of transformation of the professional activities of employees in a number of professions, that are actively changing under the influence of digital technologies towards intellectualization of activity, have been determined. A three-component model of demand in the regional labour market is justified, combining the parameters of digital competencies, target parameters of regional development and a matrix for generating competency data.

Modification of the inventory management EOQ-model factoring in the temporary value of money (TVM) and an advance payment of the order on the basis of the credit is given in this article. Its purpose is to present for the managers an appropriate modification of the EOQ-formulas for such models (both for deliveries of one nomenclature of goods, and for multinomenclature deliveries). Usage of these modifications will allow to increase the efficiency of deliveries by taking into account the specificity of appropriate cash flows, if optimisation takes into account TVM (by the scheme of simple interest). Accepted that all payments are being realised from the revenue of the previous delivery. The necessary and sufficient condition for a possibility of such payments is established. The interest rate for factoring in the TVM reflects profitability of working capital of the modelled supply chain. It is defined in a format of the model. It is noted that the optimisation of the models of this type relate with the synergetic effect of increasing the profitability of working capital.