A manufacturing foundation ontology for product life cycle interoperability

This paper presents the idea of a proposed Manufacturing Foundation Ontology (MFO) aimed at acting as a basis for the Product Life Cycle (PLC) interoperability. MFO is aimed to have the provision for introducing interoperability not only across departments but across organization as well. The proposed idea shows the development of a MFO in several layers and various levels in those layers. The foundation ontology will act as a basis for building Interoperable knowledge bases or ‘World Models’ from a library of formally defined concepts in a heavy weight ontology. A MFO must be flexible enough to allow organizations to be able to model their own domains with the flexibility to use the terms they want. Rules and axioms governing each and every concept add rigour to the semantics of the MFO and restrict the use of concepts to facilitate interoperability with a minimum effect on flexibility to model

Manufacturability verification through feature-based ontological product models

To achieve efficient, fast and cost effective production, designers must consider all the manufacturing stages a product has to go through. A case study in a manufacturing setup shows that owing to the differences in perception of an engineering component, the coordination between design and manufacturing becomes difficult. Semantic interoperability problems are therefore faced when knowledge sharing for the purpose of manufacturability verification is attempted through computer-based knowledge bases. Ontologies have a reputation for solving semantic interoperability problems. Combined with shape feature-based models of components, ontologies provide a basis for seamless knowledge sharing. This article demonstrates the use of ontologies for analyzing the manufacturability of engineering components in the early design stages. This is done by developing shape feature-based ontological models of these components and associating manufacturability knowledge with these models. To achieve this, an ontological modelling technique is proposed that uses shape feature-based geometrical models of engineering components as building blocks. The knowledge associated with these models to demonstrate their use for manufacturability verification is derived from the findings of a case study also detailed in this article. © IMechE 2012

Mediation of foundation ontology based knowledge sources

Ontologies are helpful in giving interoperable structures to sources of knowledge and information. This interoperability, however, is greatly hindered by the heterogeneity of independently developed ontologies which in turn increases the requirements for mediation systems to reconcile the differences. A core concepts ontology for a certain domain contained by a foundation ontology can be used to alleviate this problem and to facilitate the reconciliation efforts. Possible differences in the use of concepts from the core concepts to model entities in domain ontologies can be prevented by binding the domain ontology developers to some rules. These rules can be particularly useful for domain ontologies requiring some kind of traceability of their concepts in the foundation ontology. The mediation system can then use this traceability to establish similarities between two ontologies. Software applications, like the one explained in this paper, can then be developed to perform the mediation task automatically and accurately

Gap analysis of ontology mapping tools and techniques

Mapping between ontologies provides a way to overcome any dissimilarities in the terminologies used in two ontologies. Some tools and techniques to map ontologies are available with some semi-automatic mapping capabilities. These tools are employed to join the similar concepts in two ontologies and overcome the possible mismatches.Several types of mismatches have been identified by researchers and certain overlaps can easily be seen in their description. Analysis of the mapping tools and techniques through a mismatches framework reveals that most of the tools and techniques just target the explication side of the concepts in ontologies and a very few of them opt for the conceptualization mismatches. Research therefore needs to be done in the area of detecting and overcoming conceptualization mismatches that may occur during the process of mapping. The automation and reliability of these tools are important because they directly affect the interoperatbility between different knowledge sources

Enabling interoperable manufacturing knowledge sharing in PLM

Traditional approaches to integrated information sharing fall far short of meeting the requirements for the seamless sharing of knowledge to support enterprise activities through the product lifecycle. Recent advances in ontological approaches to manufacturing knowledge organisation is showing promise that a step change in knowledge sharing capability can be achieved from the application of rigorous logic based languages, combined with methods for modelling context relationships. This paper discusses the issues involved in providing an interoperable manufacturing knowledge sharing environment and proposes a manufacturing foundation ontology as a key requirement for interoperable manufacturing knowledge sharing

Knowledge sharing between design and manufacture

The aim of this research is to develop a representation method that allows knowledge to be readily shared between collaborating systems (agents) in a design/manufacturing environment. Improved mechanisms for interpreting the terms used to describe knowledge across system boundaries are proposed and tested. The method is also capable of handling complex product designs and realistic manufacturing scenarios involving several parties. This is achieved using an agent-architecture to simulate the effects of individual manufacturing facilities (e.g. machine tools and foundries) on product features. It is hypothesised that knowledge sharing between such agents can be enhanced by integrating common product and manufacturing information models with a shared ontology, and that the shared ontology can be based largely on The Process Specification Language (PSL)

Knowledge sharing between design and manufacture

Object-oriented modelling has become an established technique for product and manufacturing knowledge representation. Various models offering generalised classes and class hierarchies have been proposed for this purpose. Additional bespoke classes are however typically required for specific domain representations. This causes problems when knowledge needs to be shared between domains using different models to describe common entities. These issues are especially complex when several systems are involved. For example, a designer accessing product, manufacturing, and third party systems may face multiple definitions of components, facilities and processes. This paper proposes a model that addresses some of these issues. The proposed model can describe manufacturing knowledge without additional bespoke classes. The detailed semantics of the model are based on recent work on ontologies, notably the Process Specification Language (PSL). Whilst PSL provides detailed semantics, it is not inherently object-oriented. The integration of PSL with object-oriented modelling methods is therefore the principle contribution of this work

Knowledge reuse in manufacturability analysis

This paper proposes a knowledge representation method that supports greater reuse of manufacturing knowledge in design. The method draws on recent research into object-oriented product and manufacturing models, and problem solving agents. A research platform is proposed, and the results of a test case (based on a simplified jet engine combustion chamber) are described. The paper concludes with three basic principles of reuse, i.e. product/process separation, procedural/declarative knowledge separation, and guidelines for the optimum location of rules and constraints within product/manufacturing models

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

Verification of knowledge shared across design and manufacture using a foundation ontology

Seamless computer-based knowledge sharing between departments of a manufacturing enterprise is useful in preventing unnecessary design revisions. A lack of interoperability between independently developed knowledge bases, however, is a major impediment in the development of a seamless knowledge sharing system. Interoperability, being an ability to overcome semantic and syntactic differences during computer-based knowledge sharing can be enhanced through the use of foundation ontologies. Foundation or core ontologies can be used to overcome differences existing in more specialized ontologies and to ensure a seamless sharing of knowledge. This is because these ontologies provide a common grounding for domain ontologies to be used by different functions or departments. This common bases can be used by mediation and knowledge verification systems to authenticate the meaning of knowledge understood across different domains. For this reason, this research proposes a knowledge verification framework for developing a system capable of verifying knowledge between those domain ontologies which are developed out of a common core or foundation ontology. This framework makes use of ontology logic to standardize the way concepts from a foundation and core-concepts ontology are used in domain ontologies and then by using the same principles the knowledge being shared is verified