McLeod Institute of Simulation Sciences
Academic Certificate

Engineering Degree (five years plus thesis) given by the

University of Genoa

To:

Simon Luca Poggi

Supervisor:

Agostino Bruzzone

No:

5

Thesis Title

M&S for evaluating WLCC of new vessels and related complex systems

Summary
A new approach to evaluate the Life Cycle Cost of complex systems is proposed, as well as a methodology to combine statistical and preventive analysis based on simulation. A special approach is presented and validated over the case of the new Italian Aircraft Carrier for estimating parameters, unknown in advance, in relation to the reliability of the vessel.
Simulation is a powerful tool devoted to support shipbuilding design: its use for evaluating the whole life cycle of new vessels is a very strategic issue able to guarantee a more effective configuration management. Major point of interest is the implementation of models devoted to analyze the whole life cycle of a new aircraft carrier and to compare the expected costs and performances with existing similar types of vessels through a complex identification process; it is analyzed also the global structure of the model with some experimental results obtained in relation to the new aircraft carrier project used for validation. The goal of this research , made possible thanks to the cooperation among different institutions, is to create an advanced life cycle analysis system in order to be useful as a support for decision making in new vessels design. This research in fact puts its emphasis on the importance of the capability to estimate aspects typical of a complex "product", such a new vessel, even before its production started. In these circumstances, in fact, many of the related critical parameters could be not available at all or unknown, so it is necessary to define an approach that defines effectively a model and optimizes its tuning in order to be a useful support for decision makers.

The proposed approach is based on the development of a new architecture that integrates M&S (Modelling & Simulation) in Life Cycle Analysis and Life Cycle Cost Analysis to experiment these approaches in real applications.
Life cycle cost (LCC) is the total cost of ownership of machinery and equipment, during the whole life cycle of the product, starting from the cost of acquisitions, and then to operations, maintenance, and final decommission; LCC is used in many different case:

- Project engineering
- Maintenance engineering
- Reliability engineering

Among the different methodologies used to evaluate Life Cycle Cost the authors developed an “ad hoc” model devoted to evaluate LCC in two different ways and then they implemented it using Airmobile Carriers as a particular Test Case.
On the LCC analysis, first of all the acquisition costs had to be considered, even if they are only the initial cost and just a small part of the whole LCC, after that all the other costs, both direct and indirect, had to be evaluated.
A significant impact on the total cost have the operational and support costs because they involve some important aspects such as fuel, personnel, depot maintenance, training. These costs have also a significant importance because some parameters required in the technical specifications, for instance reliability and availability, are directly proportional to them. In fact, for instance, in order to guarantee a bigger reliability, a bigger operation and maintenance cost is required.
The impact of costs is critical in military, because of several major issues such as budget limitations, operative scenario evolution and readiness requirements. Due to these reasons it is very important to develop new models in order to be able to estimate the cost for the resources effectively required to guarantee a certain level of availability in new scenarios.
In particular, during the life cycle, detailed models are required if the goal is to relate the functions/configuration of the vessels to their implications, therefore for completing these models it is requested to collect/process a large quantity of data/knowledge that usually is not even defined during early phase of the project.
Considering these boundary aspects, the methodology applied is Lean Simulation (LS) in order to develop models for this specific application; the case presented in this paper in effect represents exactly the application area for LS and more specifically for an Early Stage Evaluation (ESE).
The Lean Simulation Approach, for this specific case, is based on the use of ad hoc techniques focusing on reation of lean models; anyway, in order to properly apply this approach, some preliminary analysis are required, so it is possible to improve the impact of modeling methodologies in this framework and to mitigate, as much as possible, constraints of M&S (Modelling and simulation) such as:

- Detailed Knowledge of the System
- Certified Data about the System
- Possibility to Test Extensively the Model

Stochastic simulation is proposed in order to address effectively complex system life cycle analysis; in effect, using this approach, it becomes possible to evaluate the stochastic phenomena such as the nature of several components as well as the dynamic interactions ongoing in the real system.
Simulation allows creating an effective quantitative methodology and identifying solutions able to improve the overall performances of a complex systems; however a trade-off analysis needs to be executed before proceeding. In effect, especially in this kind of projects, during the start up phase it is necessary to evaluate the overall obtainable benefits in system life cycle provided by developing simulation models; the importance of this analysis is due to the possibility to check the suitability of a specific application case to this methodology in relation to the additional costs introduced by simulation (even if mitigated by applying LS). In any case it is very important for decision makers to estimate a reference baseline for allocating resources to LS modeling initiatives.
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