Knowledge modeling
Explicitation of knowledge and standard specifications
Knowledge modeling is a process of creating a computer interpretable model of knowledge or standard specifications about a kind of process and/or about a kind of facility or product. The resulting knowledge model is typically stored in a database.
Knowledge-based engineering or knowledge-aided design is a process of computer-aided usage of such knowledge models for the creation of a computer interpretable model of a particular imaginary process (a process model) that is intended to take place and/or for the creation of a model of a particular facility or product (a product model) of an imaginary individual object that is intended to perform or enable such a process. The resulting process model or product model is typically also stored in a database.
The basis of a knowledge model of a process is specification of the sequence of process stages, defined by streams that have roles as inputs to process stages and whereas the same streams may be outputs of other process stages. For example:
- water shall be input in a boiler
- steam shall be output of a boiler
- steam shall be input in a heater
- condensate shall be output of a heater
- etc.
The basis of a knowledge model of an assembly physical object is a decomposition structure that specifies the components of the assembly and possible the sub-components of the components.
For example, knowledge about a compressor system includes that a compressor system consists of a compressor, a lubrication system, etc, whereas a lubrication system consists of a pump system, etc. This means that a part of a knowledge model about a compressor system will contains the following specifications:
- compressor system shall have as part a compressor
- compressor system shall have as part a lubrication system
- lubrication system shall have as part a pump system
- pump system shall have as part a pump
Such a knowledge model will be further extended with knowledge and specifications about the properties of the components, their fabrications and possibly testing and maintenance requirements.
Explicitation of document content
Knowledge modeling includes the explicitation of knowledge that is available in documents, such as design manuals, (international) standard specifications and standard data sheets. In order to make such knowledge computer interpretable it need to be transformed into a computer interpretable form. For example in the form of a system independent Gellish English expressions that canbe stored in a Database. The knowledge that is contained in documents can be modeled at various levels of explicitation. A low level of explicitation keeps large parts of the specifications in the form of natural language text. The extreme is that whole documents are related to an element in the knowledge model. For example, the knowledge that the API 617 standard contains a standard specification for centrifugal compressors can be linked to the concept compressor in the knowledge model of a compressor system as follows:
- centrifugal compressor is specified in API 617
A higher level of explicitation means that paragraphs or sentences in natural language are related to components in the knowledge model. A full explicit model means that the natural language sentences are completely transformed into data in a database structure.
For example, a specification of a minimum shaft diameter might be included in the knowledge model as follows:
- shaft diameter shall have on scale a value greater than 20 mm
The above described explicitation process results in Knowledge Models and Standard Specifications Models that enable their use for computer supported knowledge-aided design as well as for automated verification of designs.