In the dissertation was solved an actual scientific and applied task of developing of methods and means for the management of bulk carriers, considering the uncertainty of the conditions for their operation. The management of bulk carriers work was considered at two levels - on the operational level (the level of the particular voyage) and within the framework of an annual period of time for the two main variants of the commercial operation of vessels - under terms of a charter and on the basis of long-term freight contracts.
For each situation, the influence of the system of uncertainty factors in the operating conditions on the parameters of the production process was identified and reflected at a formalized level, and, as a result, on the efficiency of the vessel's operation. There were also developed appropriate mechanisms in order to ensure a given efficiency of vessels' work, taking into account the uncertainty of the conditions of their operation for each level of management.
The basis for identifying of the system of uncertainties for each alloted situation was a system model for the formation of uncertainties in the management of vessels' work, which provides the unity of a variety of productional and management-technological processes in the shipping.
There was also determined a possible negative influence of the system of uncertainty factors on the change in the main resource of a maritime vessel - carrying capacity. It is established that the main influence on the carrying capacity of a particular vessel under given conditions is rendered by the «time» factor in the form of reduction of the operational period or an increase in the elements of the voyage time.
A principle scheme of formation of the range of possible values of the main parameters of the vessel's operation at the level of the voyage and within the limits of the annual time interval was developed and characterized. The validity of the application of probabilistic approaches for the accounting of the uncertainty of operating conditions of vessels was substantiated as well.
For the level of a specific voyage, an expression of a possible reduction in the time-charter equivalent, the main indicator of efficiency, was formulated under the influence of a system of relevant factors, and methodological bases for accounting of possible deviations in the voyage parameters during the operational management of the vessels' work were developed to ensure the required level of efficiency. In particular, a calculation formula for the determination of the necessary level of increase in the freight rate is proposed, as a kind of
«compensation» for the risk, which can be used in negotiating on a freight deal to ensure a given level of efficiency.
The influence of the vessel's cargo capacity and the distance of transportation on the possible deviations of the time-charter equivalent was also researched.
Two modified approaches for the determination of the time-charter equivalent are suggested, taking into account the possible negative impact on the efficiency of the vessels' work within the annual time frame under the conditions of a voyage charter for a system of productional and commercial factors.
The specifics of the conditions of long-term freight contracts, which determines the uncertainty of the operating conditions of vessels, were established. In particular, the influence of uncertainty caused by the specific conditions of long- term freight contracts ( about cargo and ports), which leads to a possible decrease
in the volume of transport work due to a reduction in traffic volumes and an increase in transportation distances, are analyzed.
A mechanism has been developed to ensure the effectiveness of vessels' work on long-term contracts of affreightment based on the establishment of the expected time-charter equivalent for two operating conditions: for a specified number of loading/discharging ports under the contract and in conditions of uncertainty with loading/discharging ports.
An economic-mathematical model for allocation of vessels' time budget under long-term freight contracts in the conditions of interval uncertainty is developed, taking into account the fact that in a «free» from work time under these contracts, vessels can operate in an open freight market. Interval uncertainty is manifested in the fact that the parameters of the transport process, technical and operational indicators of vessels' performance and the volumes of transport work are presented in the form of ranges (intervals), which corresponds to the actual situation in the shipping.
The developed model was tested on a concrete calculation example, two methods were used to find the optimal value of control parameters, which demonstrated the possibility of finding the solution of the problem under consideration for the proposed model.
Keywords: deviations, management, operation, parameters, time-charter equivalent, uncertainty, vessel operation.
