Overview
ISO 18629-11:2005 - Part 11 of the ISO 18629 family - defines the PSL Core (Process Specification Language core). It provides a formal, machine-interpretable representation of the basic concepts common to all manufacturing processes using a concise set of axioms written in the basic language of ISO 18629. ISO 18629-11 is intended to improve interoperability between process modeling, MES/ERP, PLM and other industrial automation systems by standardizing the ontology and basic semantics for describing processes.
Key topics and technical requirements
- Core ontology and axioms: A formal set of axioms that constrain interpretation of PSL symbols and define the primitive concepts of the language.
- Primitive lexicon: Basic categories and symbols such as:
- activity, activity_occurrence, object, timepoint
- Individual markers (e.g., inf-, inf+)
- Primitive relations (e.g., before, occurrence_of, participates_in)
- Primitive functions (e.g., beginof, endof)
- Defined lexicon: Conservatively defined terms built from primitives (examples include between, beforeEq, exists_at, is_occurring_at).
- Language syntax and grammar: Specification of lexicon, grammar, and well-formed formulae consistent with ISO 18629 basic language rules.
- Conformance rules: Criteria for conformance of ontologies and process descriptions to the PSL-Core.
- Supporting specifications: Normative and informative annexes (ASN.1 identifier, KIF syntax and semantics, BNF conventions) and process description examples to guide implementation.
Applications and who uses it
ISO 18629-11 (PSL Core) is used where a common, precise representation of process knowledge is needed:
- System integrators and solution architects implementing interoperability between MES, ERP, PLM, scheduling and planning tools.
- Software vendors producing process modeling, simulation, or execution systems that must exchange process descriptions.
- Ontology engineers and knowledge-modeling teams creating domain extensions or bespoke process vocabularies that build on a standardized core.
- Manufacturing engineers and operations researchers who need formal, unambiguous process representations for automation, optimization, and analytics.
Related standards
ISO 18629-11:2005 is a foundational standard for process modeling and semantic interoperability in industrial automation, enabling consistent exchange and interpretation of manufacturing process information.