The Product Information Model

The core of the system is the Product Information Model database. This can be regarded as a comprehensive "Ship Database" containing all information about a specific project. The database is object-oriented in the sense that all design and production data stored as "objects". These "objects" are all of the types of physical items found in ship construction, for example, plates, stiffeners, The description of each type of object is formulated in such a way as to contain all the necessary technical data and/or properties which are required in order to describe a particular instance of the object. The technical data and/or properties are then used to derive the graphical representation of the object for use in symbolic sketches or in 2D or 3D views, depending on the context of the presentation. When design modifications are necessary it is this technical data which is changed rather than the graphical information, as would be the case in most other CAD systems.

The object-oriented approach, which has been adopted for the database, means that different views of the Product Information Model can be easily derived, allowing fast dissemination of the design data to various users.

The Product Information Model is a complete cohesive database describing a whole ship design and its associated production details.

Two important concepts are used in the Product Information Model implementation in order to enable the system to handle the large volume of data that represents a complete ship with good response performance and with realistic database sizes.

Firstly, all data is stored using Object Technology in which geometry is not explicitly stored, but is derived as and when needed from the stored technical data.

Secondly, a combination of Solids and Light Solids are used for model display and model development, again to give a good optimum performance. Light solids are a simplified way of storing and handling solid primitives and in which a canonical representation is used instead of a boundary representation.

Below, some of the major characteristics and benefits from the Product Information Model are listed.