MODELING OF THE DISTRIBUTION OF THE VESSELS' TIME BUDGET UNDER LONG-TERM FREIGHT CONTRACTS WITHIN CONDITIONS OF UNCERTAINTY

• Published in: Rozvitok metodìv upravlìnnâ ta gospodarûvannâ na transportì no. 69(4); pp. 15 - 25
• Main Authors: Vyshnevska, O., Vyshnevskyi, D., Onyshchenko, S.
• Format: Journal Article
• Language: English
• Published: Odessa National Maritime University 01.12.2019
• Subjects: shipping, fuzzy sets, optimization, fleet operating, contracts of affreightment
• ISSN: 2226-1915; 2415-3893
• DOI: 10.31375/2226-1915-2019-4-15-25

A model for allocation of vessels' time budget under long-term freight contracts in the conditions of fuzzy 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. Fuzzy 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 maximum, minimum and most expected, which corresponds to the actual situation in the shipping management. The proposed model allows to define: the number of vessels of a certain type, which should be taken in time charter lease to achieve specific goals and conditions; the allocation of the company's own vessels and leased vessels under long-term contracts and, accordingly, the selection of contracts (as a result of optimization, individual contracts may be identified as not effective for the company; determination of the time budget shares of vessels (own and leased), within which they will carry out transportation under these contracts, as well as time budget shares, within which they will work on the free freight market. At the same time, established values of the variables ensure the maximization of operating profit, with the consideration of it's minimum permissible boundary. Technical and operational performance of the vessels and the characteristics of contracts and indicators characterizing the situation on the freight market are presented in the form of fuzzy numbers of a triangular type, which reflects the practical availability of information (minimum, maximum, and most possible). The results obtained from the model take into account the uncertainty of the conditions formulated in the form of fuzzy numbers, describing the values of technical and operational indicators, as well as the characteristics of long-term contracts and the situations on the freight market. Practical use of the model allows shipowners to plan the work of vessels and evaluate the results of their work in the absence of complete information, based on analysts' forecasts, presented in the form of fuzzy numbers.