Operation platform design for modular adaptable ships: Towards the configure-to-order strategy

Modular adaptable ships have received growing attention in recent decades as a promising approach to handling uncertainty in future operating contexts. A modular adaptable ship can be used for multiple purposes by changing its module configuration. This configuration change is based on the ship's operation platform, which is used as a common basis for multiple module configurations. The design of an operation platform is a multi-objective problem in which designers have to deal with the conflicting requirements of multiple missions and carefully determine the interfaces that affect the configurability and flexibility of the modules. In this paper, we present an optimization model for the design of an operation platform. This determines the optimal platform design that best meets the desired capabilities of multiple missions while considering its expected lifecycle cost. A platform's capabilities are evaluated based on its multiple module configurations for individual missions. The evaluation of lifecycle cost uses operation scenarios due to its sensitivity. We implemented the model in a case study involving an offshore support vessel, for which an operation platform was designed to compete with inflexible multi-purpose ships. The results give insights into the platform design problem with opportunities for further improvement of the design.acceptedVersio

Simulation-Based Analysis of Arctic LNG Transport Capacity, Cost and System Integrity

This paper presents a design case for arctic LNG transport, where liquefied gas is shipped from the Kharasevey terminal in Northern Russia to markets in US and Europe. Based on a fleet simulation model, the trade-off between the two main performance issues related to arctic transport are investigated; namely how to maintain transport system integrity in the harsh ice conditions, while maximizing the capacity utilization in a situation with considerable seasonal variations. The fixed contract, single destination base case shows that meeting the requirements for a robust solution implies a low degree of utilization in the summer season. To improve upon this situation, several mitigating strategies are evaluated, including vessel speed and size changes, fixed and seasonally varying contract and market mix schedules, revision stop re-scheduling, storage capacity extensions and backhauling. The results indicate a high payoff from renegotiating the initial fixed schedule contract to allow for a higher degree of seasonal variations in the LNG deliveries. Further, increased storage capacity in loading port, combined with winter revision stops will have a significant impact on both fleet utilization and total system integrity. Flexible contracts that implies seasonal deliveries to the UK will help ensure continuous production and deliveries in winter season. Finally, surplus capacity gives opportunities for seasonal spot cargoes that could be exploited to increase fleet utilization rate

Assessing flexible offshore construction vessel designs combining real options and epoch-era analysis

Recent events in offshore oil and gas markets show the need for elaborate treatments of uncertainty throughout the design process and lifecycle management of maritime engineering systems. Offshore construction vessels are subject to uncertainty stemming from both economic factors modelled as stochastic processes, and from discrete factors like regulations and contract requirements. We present a simulation framework for valuation of flexible offshore construction vessels incorporating real options analysis and epoch-era analysis. Based on compliance with a set of contracts and the potential revenue to be earned from these contracts, the model maximizes expected net present value for each contract period. Benchmarking a flexible design of an offshore construction vessel against an inflexible design, we estimate the value of flexibility and find strategies for managing the design through the lifecycle. The results show that significant gains in the value of the vessel result when design changes are taken into account

Concurrent design of vessel machinery system and air emission controls to meet future air emissions regulations

Abstract In this paper we consider the reduction of air emissions from vessels during the design phase. The aim is to support ship-owners in the vessel design and in the selection of air emission controls for meeting current and future environmental regulations. We present a cost driven optimization model that is concurrently handling two mutually dependent decision problems: Machinery design and selection of air emission controls. The output of the model is the optimal machinery system for the vessel together with the optimal plan for which emission controls should be implemented and when, either during building or later during the vessel life when emission regulations make it necessary. We later extend the model to include the Energy Efficiency Design Index. We present a case study exemplifying the use of the model, and propose methods to include other performance criteria such as environmental sustainability, robustness and flexibility

An approach towards the design of robust arctic maritime transport systems

This paper describes a simulation-based approach towards the design of robust arctic maritime transport systems that are adaptable to uncertain future ice conditions. It makes it possible to simulate the performance of the transport system for various future ice scenarios and to compare various ice mitigation strategies in terms of cost. A case study is carried out to demonstrate how the approach could be applied in practice. The outcome from the case study indicates that the approach can provide valuable insights into the economics of an arctic maritime transport system and that its components can easily be modified or replaced for improved accuracy.author postprin

Planning vessel air emission regulations compliance under uncertainty

In this paper we consider the reduction of air emissions from vessels when uncertainty is taken into account. Uncertainty in the reduction effects of the different existing air emission controls is currently high and makes their selection for vessel emission regulations compliance a challenging process. We develop a two-stage stochastic optimization model that addresses this uncertainty. The model’s objective is to plan the installation of air emission controls over a specified time horizon for a vessel to comply in the most cost-efficient way with the air emission regulations. The uncertain reduction effects of the controls are modelled by a set of scenarios. The approach is applied to a case study with real data. The solution exposes the important impact of uncertainty on this problem, especially on the SO X reduction, while the CO2 reduction plan seems in this case not affected by uncertainty

An approach towards the design of robust arctic maritime transport systems

This paper describes a simulation-based approach towards the design of robust arctic maritime transport systems that are adaptable to uncertain future ice conditions. It makes it possible to simulate the performance of the transport system for various future ice scenarios and to compare various ice mitigation strategies in terms of cost. A case study is carried out to demonstrate how the approach could be applied in practice. The outcome from the case study indicates that the approach can provide valuable insights into the economics of an arctic maritime transport system and that its components can easily be modified or replaced for improved accuracy

Exploiting latent functional capabilities for resilience in design of engineering systems

In this paper, we address latent functional capabilities, capabilities that were neither intended nor recognized in the design process. We propose that latent capabilities can improve the resilience of engineering systems, enabling recovery of performance after disruptive events. Engineering systems are designed to meet their functional requirements, and have a limited ability to avoid critical failures. Normally, redundancies are put in place to reduce the impact of potential disruptions, adding to cost and complexity. An alternative is to uncover latent capabilities that can be used to recover from disruption by altering the function-form mapping. Existing design methods focus on intended, manifest functionality, and do not consider latent capabilities. With basis in design theory, we show that latent capabilities can enhance resilience, and demonstrate this using two illustrative cases. Further, we propose approaches to uncover latent capabilities in systems design, and discuss implications of using latent capabilities to enhance resilience

Influence of ship design complexity on ship design competitiveness

Complexity is discussed in design literature mainly through its negative and in some cases positive consequences. This article critically reviews and elaborates the effects of complexity on competitiveness in ship design, its directionality, and magnitude. The article introduces a model for the measurement of ship design complexity and ship design competitiveness based on predefined factors. Archival data of 100 ship design projects from eight different Norwegian designers are used as case study. Multivariate data analysis techniques are employed to study the research model. The results show a significant correlation between complexity and competitiveness in ship design, where the magnitude and directionality of influence vary among different complexity factors. Our findings provide a basis for enhancing complexity management in ship design