ISO 14649-10:2004 specifies the process data which is generally needed for NC-machining and therefore common to several machining technologies. These data elements describe the interface between the programming system (i.e. CAM system or shop-floor programming system) and a computerized numerical controller. The programme for the numerical controller includes geometric and technological information. It can be described using ISO 14649-10:2004 together with the technology-specific parts (ISO 14649-11, ISO 14649-12, etc.). ISO 14649-10:2004 provides the control structures for the sequence of programme execution, mainly the sequence of working steps and associated machine functions.

The "machining_schema" defined in ISO 14649-10:2004 contains the definition of data types which are generally relevant for different technologies (e.g. milling, turning, grinding). It includes:

• the general executables, including workplan, workingsteps and NC-functions;
• the definition of the workpiece;
• a feature catalogue containing features which might be referenced by several technologies;
• the basis for an operation definition.

Not included in this schema are the following:

• geometric items;
• representations, which are referenced from ISO 10303's generic resources;
• the technology-specific definitions, which are defined in separate parts of ISO 14649.

ISO 14649-10:2004 cannot stand alone. An implementation needs in addition at least one technology-specific part (e.g. ISO 14649-11 for milling, ISO 14649-12 for turning).

Additionally, the schema uses machining features similar to ISO 10303-224 and ISO 10303-214. The description of process data is done using the EXPRESS language as defined in ISO 10303-11. The encoding of the data is done using ISO 10303-21.