THE APPLICATION OF HYPERMEDIA IN THE FACTORY INFORMATION ENVIRONMENT.
Presented at an IEE Conference called Factory 2000, Cambridge, 1997, pp 411-415.
By Crowder RM, Wills G, Heath I, Hall W.
Abstract:
This paper examines some of the issues involved in developing a hypermedia application for use across a manufacturing enterprise. The issues addressed include: user interface, application authoring, portability of information, revision control, and communicating with external resources. To demonstrate a number of these principles a case study is used. The case study delivers training and maintenance information to operators at Pirelli Cables, Aberdare.
6. PORTABILITY OF INFORMATION.
9. COMMUNICATING WITH EXTERNAL RESOURCES.
Research on open hypermedia has been undertaken at the University of Southampton since 1989 [1]. The Multimedia Research Group (MMRG) is working in collaboration with other departments in the development hypermedia applications. One such application was undertaken with the Electrical Engineering department, which involved research into the use of open hypermedia to provide information for the cable packaging line at Pirelli Cables, Aberdare [2, 3].
Over many years of use, traditionally paper based information system have been refined. In many cases an effective and easy to use document management system exists [4]. As equipment is replaced or modernised, many of the old paper base information systems are being replaced, albeit slowly, with electronic information systems. In many industrial environments some form of information technology is in use. From the engineers using networked PCs and work stations in the design offices to fully integrated management systems. Even on the shop-floor it is not uncommon to find computer controlled systems with electronic help manuals.
As the amount of information technology increases, managing the information resources, so that the correct people can find the information easily, becomes a critical issue. While some of the general requirements for the use of hypermedia in an industrial environment, in regards to the computer science approach are described by Malcolm [5], with some solution suggest by Davis [6].
This paper looks at the way in which hypermedia can be practically used to develop an application for use in a factory environment. We will use the Aberdare case study to describe the practical solutions used and at the same time examining some of the issues involved in making the provision of information factory wide.
The Pirelli application used a commercial hypermedia package, Microcosm [7], developed at the University of Southampton [8]. Microcosm is an open hypermedia system [6] which separates the links from the data (text documents, video clips, photographs, tables, technical drawings, audio files etc.). This enables the documents to be stored in different locations, in their original format. Microcosm allows the user to navigate through the documentation resource base via a number of different link mechanisms. These are produced manually by the author or automatically by the system generated links. The links can be arranged in link databases (linkbases) to represent different cognitive and pedagogical structures. The request for actions (new document, follow links, etc.) from a user selection either from the context of the display, menu or toolbar.
The open architecture allows different processes to be incorporated into an application. The processes range from simple link creation and search algorithms to dynamic link creation, such as information retrieval and rule-base algorithms [9].
The main aims of the case study were:
To explore the potential of a model for hypermedia as an operational interface in the AMT environment, and develop extensions to the model [10].
For the case study a cable packaging line at Pirelli Cables, Aberdare was chosen, with particular emphases on maintenance and operator set-up.
Maintenance is a dynamic activity that involves highly skilled personnel [2]. To reduce costs, a change within industrial plants to multi-skilling of maintenance and operational personnel is taking place. Multi-skilling highlights a number of problems in conventional information retrieval techniques.
The project involved collating the paper manuals, working instructions, engineering drawings, data tables, and other associated information, then transferring them into electronic format. This enable a information resource database to be developed. The resource database is used to provide the user with a single access point, with which they could cross-reference and navigate though the information, without the problems listed above.
The targeted users fall into two main categories:
The traditional computer-based method has been to present and distribute text together with a limited range of graphical information, in a linear or sequential fashion. To go beyond this the user interface and the navigation tools need to be carefully designed.
This would allow the user to moving freely through the information resource database to satisfy their individual requirements, enabling them to get to the information expediently.
The industrial environment brings together users of differing computer skills. Therefore, the fix screen layout is no longer adequate. The shop-floor operator benefits from the system controlling the screen format. Where as the maintenance technician will benefit more for being able to control the layout of the documentation displayed. To allow the users to have the flexibility of control over their working environment, required of a hypermedia system, has resulted in system called SHEP (Screen Handler Enabling Process) [11] . As Microcosm is an open system this is simply a plug-in module. This solution gives the designers of hypermedia applications flexibility when creating interfaces for users of differing ability. The system can be made rigid and highly supportive for novice users and at the same time more experienced users can turn off parts of the automatic screen management in order to provide a more flexible environment.
3.2 Design of the User-Interface.
A graphical user interface (GUI) was used as the main user entry point into the system. The GUI consists of a series of screen shots of a three dimensional representation of the packaging line ( figure 1). Feedback from the users showed that the use of 3D graphics where more acceptable than photographs, for use in a GUI. User feedback (shop-floor) was gained through a flexible interview approach, encouraging the shop-floor users to suggest ideas freely.
Figure 1 Screen shoot of the 3d model of the Pirelli Line
Subsequent expert reviews of the application, using discount usability engineering [12] were used to evaluate the user interface. The results from these reviews, were used to form the guide lines, used to design the hypermedia interface in the Factory Information Retrieval Management (FIRM) project currently underway.
The largest cost in producing a hypermedia application is the authoring. As with any project, the specification sets the scope and requirements of the application, from which the documentation required for the application are identified and collated. For now, we will assume that the data is in an electronic format. Once the data has been selected and collated, the information needs to be structured to ensure that navigation is both pedagogical and easy to navigate [13].
When authoring a paradox exists, the documents (or nodes) need to be as short as possible while maintaining their meaning. This will aid updating and revision control. While at the same time, the documents need to be long enough so that the system is not continually accessing the storage medium. This is especially important if the storage medium is not physical part of the delivery system.
Computer generated links can be used to access the key words in the documents registered with the system.
While the hierarchical structure of many technical manuals and procedure, comes to the aid of the industrial author. Many of the modern word-processing packages allow the use of macros. These macros have been used to construct a linkbase automatically by making links on the headings for each section. This enables a user to access any section of a document without having to go to the contents page or index, with the author having little or no input. The levels of author input depends on the methodology used to write the original documents.
Use has also been made of modern technical drawing packages. These packages use vector line drawings and items can be drawn as blocks with attributes attached. Using these features and a read only viewer (a DXF viewer) links can be automatically made to the block names or attributes. Hence, short yet unique descriptive titles are needed. Another advantage with this method, is in the updating of the drawing. The link is made on the object, using the name or attribute. When the drawing is updated, and the object moved within the drawing, the object does not need to be re-linked.
Much time and effort is spent on how to best represent complex systems in a paper based system (drawing layouts, size, segmentation, etc.) Hypermedia offers the opportunity to break free from the limitations set by the paper medium. The system can be drawn as a complete drawing, with the user zooming in and out. To ensure that the user is aware of their position with in the drawings, ‘position maps’ need to be provided.
Authoring hypermedia applications for an industrial environment is a relatively straight forward task, if all the information is in electronic format. However, in many industrial environment, manuals, especially those from third parties (i.e. vendors) are still in paper format.
This can lead to a very time consuming and hence costly process of scanning in all the documents. It is not only the time spent scanning, but time must be set aside for checking the information. Once the process of scanning and converting a text document into an electronic format is completed, the documents are easier to update.
Unfortunately this is not the case with images, where a component is represented by a collection of pixels bound by a set of rectangular co-ordinates. If a drawing is updated, and an item moved, the link will need to be updated.
Where drawings are of poor quality, it is easier to redraw (or trace) than scan the drawings to obtain the electronic version. The problem of using different word processors is solved by using a intermediary format like Rich Text Format, which most word processors can use.
6. PORTABILITY OF INFORMATION.
Sub-systems are often used in more than one application, or more than once in an application, (for example drive units). To save time in re-authoring the same information for units at the same revision level and modification state, these sub-systems can be authored as a sub-application with separate linkbases. Therefore, larger applications can be made up of a series of preauthored sub-applications. These sub-systems can be created ‘off-line’. Hence the cost of subsequent authoring is reduced as these sub-systems are designed. It is envisaged that in long term these sub-systems will be supplied by vendors as ‘standard documentation’ i.e. electronic hypermedia manuals, pre-linked and ready to slot into the application.
In any industrial environment some form of documentation control exists. Most industrial environment will use the ISO 9000 series [14] as a minimum. Hypermedia has been successful be used to ensure that only the correct issue document is used at all time [2,3]. The method (procedures) of documentation control will vary from company to company, and the application is designed to adapt to these differences. This is achieved by not replace the companies documentation system, but working with it (see section 9). However the links themselves are sources of information as much as a line of text or a object in a drawing. Hence it is necessary for the hypermedia system, in the revision control process, to log the changes made to the application linkbases, when the document are updated. For this reasons, the author(s) have to ensure that link bases are kept in hierarchical (manual, chapters etc.)
and pedagogical structure (fault trees, etc.).
In practice the delivery computer needs to be taken to the point of use. It would be of little benefit if the shop-floor users had to walk over to a workbench to access the information.
The Aberdare case study used a pen based portable computer was used to deliver the information. The users found this easy and natural to use. To select a link the user circled the object on the screen, by tapping the screen the user is able to select a menu action. The information resource base was kept on the hard disk of the pen computer.
To enable the maintenance technicians to use both hands and still see the information required, the FIRM project is evaluating a lightweight wearable computer (called the TrekkerTM [15]). This wearable computer is voice operated with flip down eye piece, which can be moved out the way if required. The eye piece provides the user with a display, equivalent to a 14 inch monitor at approximately a meter.
There is no need to have all the information stored on a hard disk (or other storage media) physically attached to the delivery device, as Microcosm can be used for distributed information management [16]. The resource database can be on one or a number of different servers around the factory, or in the case of third party documentation, these can be on the vendors world wide web server [17]. With the distributed network a wireless Local Area Network (LAN) can be used to deliver the information.
9. COMMUNICATING WITH EXTERNAL RESOURCES.
In order to achieve the concept of a factory wide information resource, the system will have to communicate with other external resources. In our view the system must have [13]:
The access control to these external communications is carried out by a series of permissions. Allowing the hypermedia application to be opened up to the whole factory and still provide the security required.
The widespread introduction of hypermedia into an industrial environment is to a large extent governed by its acceptance by shop floor personnel. Hence the need for carefully designed of the user interface, navigational aids, the method of delivery and along with the choice of equipment that is to be used.
The advantages of the open hypermedia system approach lie in its ability to:
Industrial systems have been traditionally designed and used with the paper base system in mind. Hence there needs to be a slight shift in thinking, to allow the information technology to be used to it’s fullest advantage. To author an industrial hypermedia system can be made much simpler by using the full functionality of modern application packages.
The authors acknowledge the EPSRC for funding the work under grant numbers GR/H/43038 and GR/L/10482 , and Pirelli Cables, Aberdare for allowing us to use their site for a case study.