Traceability in ship design

Abstract

Traceability in complex ship design involves keeping track of the evolving relations between need, requirements and design. Such traceability is not fully developed in the current design process at DMO due to divisions in the design process and between design tools. This thesis proposes to use a single information model to facilitate traceability by connecting the need, requirements and design in a single database. Besides enabling traceability, such an information model can also be used to support modern modelling design tools. In the early design stage of naval vessels – the preliminary design phase – the capability, technical feasibility and affordability of a new ship are defined. Interactions between these three aspects are opaque and rely on the need for a new naval vessel and supporting requirements and preliminary design(s).
Determining the need, requirements and design is in this thesis considered to be a ‘wicked problem’. In such problems, information gained by developing solutions helps define the problem itself. However, these solutions can only be determined with a certain interpretation of the initial problem. This results in many (evolving) interactions between the need, requirements and design in the ship design process as one is needed to define the other. With the help of Systems Engineering and Requirements Engineering information and relations in a ship design process can be determined and structured. These engineering fields are widely applied, and current technology enabled the development of computer aided approaches incorporating design theory, including computer aided traceability. One of the current developments in design approaches is the introduction of model-based approaches, which creates the possibility to actively manage more relations and interactions in the design process. Model based approaches such as the Design Structure Matrix are used to visualise relations between information, and Axiomatic Design enables the decomposition and creation of complex relations. A different approach to modelling in design processes is the use of Knowledge Based Engineering. Knowledge Based Engineering field aims to capture not only the relations and interactions between information in design processes, but also ‘knowledge’ about the ‘how’ and ‘why’ in these processes. Each of these model-based developments relies on, or enables, traceability of information. However, having a program capable of supporting an information storage to support these approaches remains difficult to achieve. For this purpose, Shipbuilder software was created to support transparent storage and management of information. In this thesis, theories for modelling approaches, Systems and Requirements Engineering and the DMO design process have been combined. This resulted in one information structure, applied in the Shipbuilder application, which enables traceability. To show that the proposed information model can model a ship and supports traceability, a case study has been performed. A small model of both an S- and L-frigate has been created to show how traceability can be performed in this information model.