# A Multi-Model Ontological System for Intelligent Assistance in Laser Additive Processes
## 3 Results
### The Ontology of the Case Database  
Based on initial testing results, we substantially revised and expanded the ontology of the archive (library) of laser processing TO protocols (previously called ontology of technological operations) [27]. The enhanced ontology uses fragments of equipment and materials reference database ontologies (Figure 7). Figure 7: A fragment of the ontology for the archive of laser processing technological operation protocols. The TO protocol includes the following sections: general information about the TO; environmental conditions when performing the TO; terms of reference for the TO; the specification of equipment for performing the TO; information about preliminary preparation of the substrate or the part; the working gas environment created; key process parameters for performing the TO; possible controlled cooling of the part or the workpiece; and the result of the TO. General information about the TO includes the TO designation, the protocol number, the deadline, the purpose and the location in which the TO is performed. Environmental conditions include the ambient temperature, relative humidity, and atmospheric pressure of the environment in which the TO has been performed. This information is significant because the technological equipment must operate under conditions where its working temperature will be higher than the dew point of technological (process) gases. The terms of reference for the TO include the following sections: requirements for the result of the TO; the object to be processed which is a substrate or a part; the feedstock material used to perform the TO which is a metal powder (there may be more than one) or metal wire; process gases used to perform the TO. The Section containing the requirements for the result consists of the following subsections: geometric characteristics, defects, elemental composition, microstructure and properties of the deposited material. These sections may be completed selectively, depending on the task being performed. In accordance with ASTM F3413-19, there are four types: the manufacture of a new part/workpiece, the repair of a worn or damaged part, the application of a functional coating on the part/workpiece (surface modification), and the build-up of functional or structural elements on the part/workpiece. A separate type of task to perform may involve conducting research studies to identify regimes of the TO that are suitable for a specific practical application. In the geometric characteristics section, a file describing the digital model of the part is placed (usually, in either the *.stl or *.amf format). Alternatively, depending on geometrical shape, one can specify a set of dimensions of the geometrical characteristics of the target result, by which it needs to be evaluated. The defects section lists which defects (and their characteristics) are acceptable (and within which limits), and which must be entirely absent. Porosity is a typical example of a defect that is permitted within certain thresholds. In the elemental composition section, one can specify the elemental (chemical) composition that is necessary/desirable to obtain as a result. In the microstructure section, the preferred microstructure of the deposited material can be specified. The properties section can list the requirements for the characteristics (properties) of the deposited material that must be obtained as a result of performing the TO. It is very important that the markup specified in the ontology regulates that the names of chemical elements, defects, properties (and their values), etc., as well as their units of measurement, should be selected from the appropriate reference databases while forming the protocol. Additional ontological agreements consist in the fact that the specified values for defects, properties, etc., should belong to the range of possible values that are defined for them in the relevant reference databases. These ontological agreements ensure data consistency and interoperability across the knowledge system.