The rank correlation method application at the conceptual design stage of offshore technical structures

Abstract

In the present work, a multi-criteria task of choosing types of offshore technical structures at the stage of conceptual design was undertaken. Criteria that allow evaluate and compare the offshore technical structures types were defined. Features of defining the criteria for marine structures have been established; at the same time, the indicators, including calculation assessments and regulated by normative documentation (the Register Rules), were not considered as criteria. The marine technical structures type for a given range of depths is determined with a minimum amount of initial data as a result of the researches at the conceptual design stage. An assessment of the consistency of opinions of the expert group was carried out.
The aim of the work was to determine the possibility of applying the methods of rank correlation in the design of marine technical structures at the conceptual design stage (that is, at the initial stage with a minimum amount of input data) and the applicability limits of various offshore technical structures for the shelf development. To solve the problem, the principle of unity was used, when the system (the offshore technical structure) was considered both as a whole and as a set of elements (criteria). Based on the method of expert assessments, the choice of the structure type was made at the initial stage of design, in conditions when the input data is practically absent. The Delphi method was chosen for the expert survey procedure. The experts presented their judgment assessed by ranking of the proposed options on the 10-point assessment scale. The ranking of criteria was determined using the hierarchies’ analysis method. The consistency degree of the expert group was evaluated using the Spearman's rank correlation coefficient.