Robert I. M. Young

Manufacturing knowledge sharing in PLM: a progression towards the use of heavy weight ontologies

The drive to maximize the potential benefits of decision support systems continues to increase as industry is continually driven by the competitive needs of operating in dynamic global environments. The more extensive information support tools which are becoming available in the PLM world appear to have great potential but require a substantial overhead in their configuration. However, sharing information and knowledge in cross-disciplinary teams and across system and company boundaries is not straightforward and there is a clear need for more effective frameworks for information and knowledge sharing if new product development processes are to have effective ICT support. This paper presents a view of the current status of manufacturing information sharing using light-weight ontologies and goes on to discuss the potential for heavyweight ontological engineering approaches such as the Process Specification Language (PSL). It explains why such languages are needed and how they provide an important step towards process knowledge sharing. Machining examples are used to illustrate how PSL provides a rigorous basis for process knowledge sharing and subsequently to illustrate the value of linking foundation and domain ontologies to provide a basis for multi-context knowledge sharing.

A review of computer-aided Simultaneous Engineering systems

World-wide markets are becoming increasingly competitive, and in order to sustain market share organisations are developing a customer-oriented approach for designing and producing high-quality, high-value products. The philosophy of simultaneous engineering has been proposed as a potential means of improving product development practice. This philosophy involves simultaneously satisfying the functionality, reliability, manufacturability, and marketability concerns of new products in order to reduce product development time and cost, and to achieve higher product quality and value. In this paper the concept, objectives and principles of simultaneous engineering are introduced. The past and present research into computer-aided systems for the support of simultaneous engineering is present, reviewed and classified. This will both allow the current state of the art to be assessed, and enable the identification of future research that will contribute to the realisation of computer aided support for Simultaneous Engineering.

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.

Application of IDEF0, IDEF3 and UML methodologies in the creation of information models

The importance of information models is widely recognised by the computer integrated manufacturing research community. However, improved methods are still needed to assist the developer in the definition of information model structures. Currently available methods and standards can only help in certain stages of the information modelling process. This paper explores the benefits of combining three methodologies in the definition of the structure of information models that support applications through the product life cycle. While all the methodologies that are currently used in information modelling have some advantages, they also have weaknesses. This paper shows howthe combined use of IDEF0, IDEF3 and UML methodologies can be used to advantage in the context of the Open Distributed Processing (ODP) standard ISO10746. The combination of these methods means that the weaknesses of each can be counteracted by the strengths of others. IDEF0 is commonly used, with some success, to model enterprise activities and information flows. However its ability to describe information is weak and it cannot model process flows. IDEF3 offers both a process flow capability that can be linked to IDEF0 and an ability to model information in object centred descriptions. The results of the application of these methodologies provide the required information for the top levels of the RM-ODP. Furthermore, both methodologies have been proved to be very good means of communication with the collaborating companies. The results obtained with the IDEF3 method provide key information for the creation of classes with attributes and operations that can then be used in the design of computational systems using UML. The resulting UML class diagrams show the relationships and inheritances that are the main input to the creation of object-oriented databases that hold the data of the information models. These combined methods have been used to model the information required through different stages of the product life cycle for the assembly of large electrical machines and have been shown to provide an improved definition of the relationships between the stages of information model definition.

Design of a manufacturing knowledge model

A manufacturing model is an information and knowledge model that describes the manufacturing capability of a particular organization. This work contributes to the area of information and knowledge structure to support manufacturing decisions. The structures of the manufacturing model have been defined to achieve suitable access to, and maintenance of, the manufacturing knowledge. Emphasis has been made on investigating a suitable manufacturing model structure in order to readily access manufacturing knowledge related to process planning activities. The aim of this research was to design a manufacturing knowledge model (MKM) and demonstrate its functionality through experimental software. This paper presents requirements for a new MKM, proposes its structure and describes its design.

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.

Utilizing information and knowledge models to support global manufacturing co-ordination decisions

In recent years, researchers have devoted great attention to global manufacturing co-ordination (GMC). The focus of GMC is on integrating the activities across both functions (supply, manufacturing, distribution) and geographic areas, that is not only on synchronising and smoothing production operations but also on product shifting. Successful international co-ordination and collaboration requires information integration and sharing. Representation and provision of a common source of high quality information, through information models, is one of the fundamental requirements of effective information integration and sharing. This paper proposes an approach that utilizes a combination of information and knowledge models to support GMC decision-making. Three models have been identified and their structures have been defined and modelled using Rational Rose UML. An experimental system, based on the object-oriented DBMS ObjectStore and Visual C + + , has been constructed and used to explore the approach taken. This has shown that the new structures of the three models defined in this paper can capture the required information and knowledge, and that these provide effective information and knowledge support for GMC decisions.

A manufacturing model to enable knowledge maintenance in decision support systems

Modeling manufacturing knowledge is a requirement to design a decision support system. The research reported in this paper defined a Manufacturing Facility Information and Knowledge Model (MFIKM); this model allows the storage, access, and management of both information and knowledge related to the manufacturing facility. Major emphasis was placed on process knowledge and resource knowledge to support process planning decisions. This work also explains the relevance of using different types of knowledge categorization. This paper argues that by using the novel Knowledge Maintenance Life Cycle as a method to maintain knowledge, it is possible to capture new and valuable machining knowledge using different types of representations. An experimental software application is presented to demonstrate the research ideas.

Methods for the capture of manufacture best practice in product lifecycle management

The capture of manufacturing best practice knowledge in product lifecycle management systems has significant potential to improve the quality of design decisions and minimise manufacturing problems during new product development. However, providing a reusable source of manufacturing best practice is difficult due to the complexity of the viewpoint relationships between products and the manufacturing processes and resources used to produce them. This paper discusses how best to organise manufacturing best practice knowledge, the relationships between elements of this knowledge plus their relationship to product information. The paper also explores the application of UML-2 as a system design tool which can model these relationships and hence support the reuse of system design models over time. The paper identifies a set of part family and feature libraries and, most significantly, the relationships between them, as a means of capturing best practice manufacturing knowledge and illustrates how these can be linked to manufacturing resource models and product information. Design for manufacture and machining best practice views are used in the paper to illustrate the concepts developed. An experimental knowledge based system has been developed and results generated using a power transmission shaft example.