Collaboration and Process Modelling in Engineering and Business - Implementation

New models can be produced by editing the ontology of sub-ontologies, or creating new ontologies or sub-ontologies. Ontologies are translated to systems/models and sub-ontologies are translated to sub-systems/models. So, different engineering process models could be produced by representation in different types of ontologies, and this could allow further different kinds of process models/systems, e.g. business process models.

The intention is to produce new modelling classes/items as required and domain experts would edit taxonomies/sub-ontologies and specify the relationships of classes and the equations to be used, via a visual user interface. These relationships and equations when evaluated and translated will produce computer code. The ontology centre holds definitions of nodes representing information, equations, and calculations to be performed. Equations relate the items in the taxonomies, and models can be automatically produced via a recursive translation tool to provide a template for the generation of a further model(s). The intention is to make it easier to interact with and change the models, and thus share information, an example interface, a section from a model produced automatically, is shown in figure 1. This example is based on aircraft wing manufacture. Code for this is produced from the semantic relationships, and the process model is translated/translatable to multiple representations in different languages and views. The information is saved using a generic structure that defines all relationships in a shared database. This enables structuring and automated queries of information. The decision support tool Vanguard Studio (2009) reads this information and represents it as colour-coded nodes according to which taxonomy it is from. Code automatically queries the taxonomies that make up the ontology and links the information required for the model. The code builds in all the links required for the equations, and thus links information from different taxonomies. This code can be reused for any modelling problem, it builds the equations and follows the links, thus the decision support tool can perform inferencing and so produce results.

Figure 1 shows how the process modelling tool automatically constructs and represents information, visualises an equation and calculates a result. Colour coded nodes represent processes, parts and resources, extracted, as needed, from the ontology. This illustrates how taxonomies/sub-ontologies can be automatically linked, and this can proceed with large scale process models. This example illustrates how an 'Area' is calculated, and that this forms part of the branch showing the 'Hand Lay-up Tool Cleaning Cost', which is consequently passed into other calculations. Calculations using information from all the taxonomies are linked as required in this example.




Figure 1 - Ontology to Model Conversion

The ontology(ies) and model(s) can then be searched and navigated online. The example below (figure 2) illustrates how it is possible to enable refining a search by visualising all the items present in sub-categories of the main category found in the search. This example illustrates the interface for making a search. In this example the user wants to retrieve all the information related to a spar (aircraft wing component).




Figure 2 - Semantic Search interface

The result is shown as a series of trees for each item that contains the word spar. Each keyword match is the root of a tree. Each tree shows the item found and all its children and attributes. The example below (figure 3) shows an image of the top part of the results, this is part of the branch for the first item returned.



Figure 3 - Results from semantic search

The information is held in linked and related taxonomies/sub-ontologies so it is not HTML that is being searched but the taxonomy itself. Because the information is held in a structured way, it is much more likely that searchers will find what they are looking for, because the search can follow the relationships represented in the taxonomy. One of the key objectives of Semantic Web research and Web 2.0 is to make this kind of search possible over the web as a whole. The Semantic Web is a longer-term vision for structuring and managing information over the web and Web 2.0 is the shorter-term practical implementation of techniques, which can ease current information search and management problems. A web interface has been developed for Protégé (WebProtege). An example of the use of this is figure 4 where a search is made for information on the cure cycle for composites manufacturing. This search is possible as WebProtege has succeeded in providing a web based interface for displaying and searching ontologies, so providing an additional way to enable web access to the test ontologies created for this research.


Figure 4 - Web Protégé Interface

The next stage of this problem is to enable interaction and modelling with the returned information. A project was created called Bitriple by Leaver (2008), to enable end user functionality for this kind of web-based ontology construction and search. The application provides a facility to edit an ontology/ies and instances, and provides tree-based visualisation of the ontology (as shown in the example below). This example illustrates creation of an online aircraft wing ontology. Wing component sub-ontologies created using Protégé can be translated for the Bitriple application to be represented as RDF/XML. An application could be built as an extension to Bitriple to perform calculations and modelling using the information stored. This could assist in allowing domain expert end user programmers/modellers to create models. Such web applications provide an alternative to spreadsheets, and to single computer based programs; and if installed on a network server, such applications can provide a collaborative model development environment. This would fit in well with both Semantic Web, and Web 2.0 approaches to knowledge creation, allowing structured representation and navigation of information, and end user interaction, collaboration, customisation and programming via the web. Collaboration can aid people to agree on terminology, and standardisation of calculations used such as for cost rates and currencies. RDF information can be searched with SPARQL, which is used to search the Bitriple application.

A screenshot (figure 5) from the Bitriple application, of ontology creation for an aircraft wing, is shown below :-



Figure 5 - Bitriple Ontology Creation Screenshot

References

Leaver, N. (2008) Using RDF as an Enabling Technology. MSc. Dissertation, University of the West of England, Bristol.

Vanguard Modelling Wiki [online]. Available from: http://wiki.vanguardsw.com/bin/browse.dsb?dir/Engineering/Aerospace/ [Accessed 21st August 2009].