A conditional value-at-risk based methodology to intermediate-term planning of crude oil tanker fleet

Optimum Composition of Charter Contracts for the Renewal of the Fleet of Offshore Support Vessels Considering Uncertainties: A Literature Review

“…On the side of the charterer, the bibliographic review carried out by Siddiqui and Verma [11] covers two main areas: fleet management and charter contracts and options. According to the authors, at the strategic level of fleet management, Dantzig and Fulkerson [20] were the first to consider both fixed costs of fleet acquisition and variable transport costs; Jin and Kite-Powell [21] proposed a model based on optimal control theories to deal with the scheduling of vessel replacement and utilization; Meng and Wang [15] presented a dynamic programming model with scenario generation for the problem of multi-period fleet development and deployment; Fagerholt et al [22] considered uncertainty in planning and developed a decision support methodology that combined Monte Carlo simulation for the parameter estimation and an optimization model for industrial shipping applications.…”

“…At the tactical level, the authors cite Al-Yakoob and Hassan [23], who assessed charter contracts to facilitate routing and scheduling a fleet of heterogeneous vessels, and indicate the readings by Christiansen, Fagerholt and Ronen [24] and Christiansen, Fagerholt, Nygreen and Ronen [25]. Siddiqui and Verma [11] also point out that although much of the works on the subject indicates spot contracts in fleet adjustment decisions, complex contracts and their options are also being used for this purpose.…”

“…In the oil transportation sector, according to Siddiqui and Verma [11], a variety of short to medium term charter contracts, such as single voyage spot charter and over-thecounter contracts, and freight futures contracts are traded on several freight exchanges. The authors point out, however, that because of the lower hedge efficiency and the difficulty of the market to deal with the demand for specific route contracts, the future contracts were replaced by the mostly over-the-counter freight agreements [30][31].…”

“…Many factors need to be taken into account when defining the best set of charter contracts (modalities, quantities and durations of contract). Among these factors, the following stand out: (i) Offshore support logistics; (ii) Demand to be served; (iii) Chartering prices; and (iv) Legislation and regulation of maritime transport [6][7][8][9][10][11]. Figure 1 shows the relationship between these four factors in the definition of the problem.…”

“…Offshore support operations consist of cargo transportation and storage activities carried out by vessels supporting E&P services at MUs. From the logistic point of view, the offshore support operations cover the handling of loads of weights, formats and varied types, as well as the planning of vessels with different specialties, service rules and operational restrictions [7][8][9][10][11][12]. According to Figure 1, the logistics of supporting the MUs, or offshore support logistics, is composed of four basic elements: maritime units; inputs (and services) consumed by MUs; support vessels; and maritime terminals [8].…”