An Investigation into the Application of Formal Decision Making Techniques to Design Alterations and Additions (As&As) for Vessels of the Royal Fleet Auxiliary (RFA)
The Royal Fleet Auxiliary (RFA) is a flotilla of ships, owned by the United Kingdom (UK) Ministry of Defence (MoD), which serves to resupply naval vessels during worldwide operations. Design Alterations and Additions (As&As) are implemented throughout their service lives in order to ‘Upgrade’ and ‘Update’ their capability. This research offers an original contribution to knowledge by applying formal decision making techniques to A&A reasoning in a way that, to the best knowledge of the researcher, has not previously been implemented as an integral part of the in-service design control process for RFA ships. In delivering this contribution, Multi Attribute Decision Making (MADM) techniques are investigated and applied. Three MADM techniques are applied: SAW (Simple Additive Weighting), AHP (Analytic Hierarchy Processes) and TOPSIS (Technique for Order of Preference by Similarity to Ideal Solution). Application of these techniques defines the scope boundary and so rules out exhaustive investigation into the wider decision making approaches that could form the focus of future research. Literature reviews indicate that formal decision techniques have been extensively studied and applied – seemingly to the point of saturation. For this reason, the research does not claim to have developed new techniques. Rather, the contribution to knowledge lies in the systematic application of the techniques. In this respect, a niche topic is identified involving the implementation of As&As during Fleet Time (FT). Investigation results in the systematic identification and categorisation of the Risk Factors (RFs) constraining FT implementation. Two different techniques (SAW and AHP) are applied to FT As&As. The outcomes demonstrate a consistent trend and so offer mutual assurance. In addition, comparison of the techniques indicates that, whilst SAW offers a convenient and intuitive approach, the AHP imposes a higher cognitive burden. This is regarded as significant by the researcher since As&As are subject to schedule and cost constraints, whereby pragmatic and proportional approaches are more likely to find programme acceptance. Based upon an actual decision involving the selection of materials for a ship sea water system, TOPSIS is used to evaluate the options against key criteria. A sensitivity analysis indicates that selection will be influenced in the direction of the criteria weighting. Since ‘procurement cost’ is an important criterion for As&As, the thesis demonstrates a methodology for the delivery of robust cost estimates. This involves the treatment of cost uncertainty using risk analysis software based upon the Monte Carlo technique. The researcher consolidates studies into systematic decision methodologies for As&As. Credibility is claimed since methodologies are based upon established techniques and tested against A&A examples. Credibility is also claimed from the theme, running throughout the thesis, that the studies build upon the professional experience of the researcher and involve engagement with Suitably Qualified and Experienced Personnel (SQEP).
TC Hydraulic engineering. Ocean engineering, TJ Mechanical engineering and machinery, VM Naval architecture. Shipbuilding. Marine engineering
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