Nitishal Chungoora

A model-driven ontology approach for manufacturing system interoperability and knowledge sharing

The requirements for the interoperability of semantics and knowledge have become increasingly important in Product Lifecycle Management (PLM), in the drive towards knowledge-driven decision support in the manufacturing industry. This article presents a novel concept, based on the Model Driven Architecture (MDA). The concept has been implemented under the Interoperable Manufacturing Knowledge Systems (IMKS) project in order to understand the extent to which manufacturing system interoperability can be supported using radically new methods of knowledge sharing. The concept exploits the capabilities of semantically well-defined core concepts formalised in a Common Logic-based ontology language. The core semantics can be specialised to configure multiple application-specific knowledge bases, as well as product and manufacturing information platforms. Furthermore, the utilisation of the expressive ontology language and the generic nature of core concepts help support the specification of system mechanisms to enable the verification of knowledge across multiple platforms. An experimental demonstration, using a test case based on the design and manufacture of an aerospace part, has been realised. This has led to the identification of several benefits of the approach, its current limitations as well as the areas to be considered for further work.

Towards a formal manufacturing reference ontology

Due to the advancement in the application of Information and Communication Technology (ICT), manufacturing industry and its many domains employ a wide range of different ICT tools. To be competitive, industries need to communicate effectively within and across their many system domains. This communication is hindered by the diversity in the semantics of concepts and information structures of these different domain systems. Whilst international standards provide an effective route to information sharing within narrowly specified domains, they are themselves not interoperable across the wide range of application domains needed to support manufacturing industry due to the inconsistency of concept semantics. Formal ontologies have shown promise in removing interpretation problems by computationally capturing the semantics of concepts, ensuring their consistency and thus providing a verifiable and shared understanding across multiple domains. The research work reported in this paper contributes to the development of formal reference ontology for manufacturing, which is envisaged as a key component in future interoperable manufacturing systems. A set of core manufacturing concepts are identified and their semantics have been captured in formal logic based on exploiting and extending existing standards’ definitions, where possible combined with an industrial investigation of the concepts required. A successful experimental investigation has been conducted to verify the application of the ontology based on the interaction between concepts in the design and manufacturing domains of an aerospace component.

The configuration of design and manufacture knowledge models from a heavyweight ontological foundation

Problems related to knowledge sharing in design and manufacture, for supporting automated decision-making procedures, are associated with the inability to communicate the full meaning of concepts and their intent within and across system boundaries. To remedy these issues, it is important that the explicit structuring of semantics, i.e., meaning in computation form, is first performed and that these semantics become sharable across systems. This paper proposes an expressive (heavyweight) Common Logic-based ontological foundation as a basis for capturing the meaning of generic feature-oriented design and manufacture concepts. This ontological foundation serves as a semantic ground over which design and manufacture knowledge models can be configured in an integrity-driven way. The implications involved in the specification of the ontological foundation are discussed alongside the types of mechanisms that allow knowledge models to be configured. A test case scenario is then analysed in order to further support and verify the researched approach.

Towards the ontology-based consolidation of production-centric standards

Production-centric international standards are intended to serve as an important route towards information sharing across manufacturing decision support systems. As a consequence of the textual-based definitions of the concepts acknowledged within these standards, their inability to fully interoperate becomes an issue, especially since a multitude of standards are required to cover the needs of extensive domains such as manufacturing industries. To help reinforce the current understanding to support the consolidation of production-centric standards for improved information sharing, this article explores the specification of well-defined core concepts that can be used as a basis for capturing tailored semantic definitions. The potentials of two heavyweight ontological approaches, notably Common Logic (CL) and the Web Ontology Language (OWL), as candidates for the task are also explored. An important finding regarding these two methods is that while an OWL-based approach shows capabilities towards applications that may require flexible hierarchies of concepts, a CL-based method represents a favoured contender for scoped and facts-driven manufacturing applications.

Towards expressive ontology-based approaches to manufacturing knowledge representation and sharing

The present capability that ontological approaches offer to formally represent and share manufacturing knowledge is dependent on the choice of ontological formalism. Currently, there exists a spectrum of these formalisms, which is being subjectively exploited across multiple domains in design and manufacture. Hence, there is an important prerequisite to achieve an understanding of which family of formalism strictly enables the expressive capture of semantics to progress towards meaningful information and viable knowledge sharing. This article analyses the relative strengths and weaknesses in employing a ‘lightweight’ ontology versus a ‘heavyweight’ version of the ontology to represent and share knowledge between multiple domains in injection moulding design and manufacture. A pertinent direction, from an ontology perspective, is then exposed as a prescription for the improved capture and dissemination of formal semantics, to support multi-domain knowledge sharing.

Extending product lifecycle management for manufacturing knowledge sharing

Product lifecycle management provides a framework for information sharing that promotes various types of decision-making procedures. For product lifecycle management to advance towards knowledge-driven decision support, then this demands more than simply exchanging information. There is, therefore, a need to formally capture best practice through-life engineering knowledge that can be fed back across the product lifecycle. This article investigates the interoperable manufacturing knowledge systems concept. Interoperable manufacturing knowledge systems use an expressive ontological approach that drives the improved configuration of product lifecycle management systems for manufacturing knowledge sharing. An ontology of relevant core product lifecycle concepts is identified from which viewpoint-specific domains, such as design and manufacture, can be formalised. Essential ontology-based mechanisms are accommodated to support the verification and sharing of manufacturing knowledge across domains. The work has been experimentally assessed using an aerospace compressor disc design and manufacture example. While it has been demonstrated that the approach supports the representation of disparate design and manufacture perspectives as well as manufacturing knowledge feedback in a timely manner, areas for improvement have also been identified for future work.

A Framework to Support Semantic Interoperability in Product Design and Manufacture

Problems related to knowledge sharing in product design and manufacture, for supporting automated decision-making procedures, are associated with the inability to communicate the full meaning of concepts and their intent within and across system boundaries. This chapter proposes a Semantic Manufacturing Interoperability Framework (SMIF) to support interoperable design and manufacture knowledge at the semantic level. The framework uses a heavyweight ontological underpinning and provides a logic-based approach for the reconciliation of domain semantics. The framework has been implemented and the important findings have been documented in this chapter.

A Manufacturing Core Concepts Ontology for Product Lifecycle Interoperability

This paper proposes a manufacturing core concepts ontology (MCCO) aimed at providing support for product life cycle interoperability. The potential focus of the work is interoperability across the production and design domains of product lifecycle. A core set of manufacturing concepts and their key relationships are identified in MCCO. Semantics are captured formally through heavyweight logic using rigorous rules and axioms. Three different levels of specialization have been identified according to the degree of specialization required. Each level provides an immediate route to interoperability for the concepts specialized from that level. MCCO enable knowledge sharing across design and production domains through core concepts. A successful initial experimental implementation has been done to demonstrate the working of MCCO.

Semantic Interoperability Requirements for Manufacturing Knowledge Sharing

Nowadays, sophisticated Computer Aided Engineering applications are used to support concurrent and cross-enterprise product design and manufacture. However, at present, problems are still encountered whenever manufacturing information and knowledge have to be communicated and shared in computational form. One of the most prominent of these problems is concerned with semantic mismatches, which impinge onto achieving seamless manufacturing interoperability. In this paper, the possible configuration of frameworks to capture semantically enriched manufacturing knowledge for manufacturing interoperability is being discussed. Ontology-driven semantic frameworks, based on explicit definitions of manufacturing terminology and knowledge relationships, offer an attractive approach to solving manufacturing interoperability issues. The work described in this paper defines Hole Feature ontological models in order to identify and capture preliminary semantic requirements by considering different contexts in which hole features can be described.

Exploiting unified modelling language UML as a preliminary design tool for Common Logic-based ontologies in manufacturing

This paper proposes a particular method which utilises the unified modelling language (UML) as a design visualisation tool for modelling ontologies based on the Common Logic knowledge representation language. The use of this method will enable Common Logic ontological concepts to be more readily accessible to general engineers and provide a valuable ontology design aid. The method proposed is explored using the knowledge frame language (KFL) which provides constructs to facilitate ontology building and is built on Common Logic. The major constructs of KFL are briefly defined and a description of how each construct may be represented in UML is given. Examples are presented showing how the constructs may be modelled in UML and a Common Logic-based implementation founded on a UML design is illustrated and discussed. The manufacturing domain is utilised as an experimental basis for demonstrating the proposed method.