Model solutions

Next-generation CAD programs are claimed to produce technical illustrations that could enhance collaboration between engineering and technical data. Charles Clarke explains.


To most people the main elements of a product lifecycle management (PLM) system are software to generate geometry supported by a data management application to keep track of all the files.

Yet many PLM vendors forget the importance of user and service manuals — the natural extension into product support. No product, from car stereos to aircraft carriers, can make it to market or be maintained within it without manuals of some kind.

Yet technical documentation such as user manuals is becoming of greater interest to industry. Complex products require that whole-life costs be defined and understood early on in the program. The cost of product support, enabled by technical documentation, needs to be analysed as early as possible. That analysis must influence design.

All the documentation needs to be created alongside the products it describes. And with increasing product variety, documents also need to be tailored to specific products or members of product families.

In many organisations operations are fragmented and use several systems which results in extra costs and effort. Illustrators are creating and re-creating custom versions of isometric CAD drawings using their preferred software tools (or sharp pencils). These are then sent to the authors, who assemble the illustrations alongside their text.

There is generally a multitude of applications from MS-Word, to Illustrator, Publisher and Acrobat that can help get the technical documentation job done. But none of these is tightly integrated in any real sense to the core PLM application.

PLM vendor PTC, on the other hand, made a strategic decision in 2005 to develop a Dynamic Publishing application suite that would be tightly integrated within its PLM offering.

That year the company acquired enterprise publishing market leader Arbortext, one of the pioneers of mark-up technology. This strategy was enhanced in October the following year with the acquisition of leading technical illustration software provider ITEDO.

PTC made ITEDO ISODraw, ISODraw CADprocess and ISOView solutions an important part of its Arbortext product family. This meant PTC could provide extensive 2D and 3D technical illustration capabilities and further enhance its 3D interactive content for technical publications. Then, in November 2007, PTC acquired Logistics Business Systems (LBS), an integrated logistics support (ILS) solutions provider to the Aerospace and Defence industry. LBS solutions are integrated with PTC Arbortext to offer provisioning, training and e-learning and logistics support analysis.

As a result of this acquisition, PTC claims it is the only PLM vendor able to provide ILS solutions that meet S1000D — the international specification for technical publications.

Traditionally, technical illustration has been an isolated part of the design and manufacturing process, which generally comes after everything else is complete. The illustrator would normally use a specially-prepared 2D drawing as input, usually on paper.

But using programs such as ISODraw will allow users to produce technical illustrations that could possibly enhance collaboration between engineering and technical data. Rather than being incumbent on engineering to ‘re-purpose’ information specifically for technical use (such as re-orientating CAD models to suit the purposes of technical manuals), models can be manipulated by the illustrator to meet the needs of technical manuals. As a result, the publications department becomes a ‘low maintenance’ output, which could lead to savings in cost and information.

The main benefits of ISODraw illustrations are speed and smaller file size. A typical ISODraw engine assembly illustration is about 450kb, less than 50 times smaller than a CAD file for the same thing. So where you need to send economical ‘sketch type’ information derived from CAD files or for web illustrations, this software is perfect.

Traditional publishing software can contribute to inconsistencies in the sequence and structure of information and forces redundant processes and multiple manual document updates. Yet PTC claims the Arbortext content publishing system will streamline and automate the process and eliminate costly inefficiencies. It exploits XML authoring (Arbortext Editor), technical illustration creation (ISODraw) and content and process management (Arbortext Content Manager). With the dynamic enterprise publishing capabilities of Arbortext (Arbortext Publish Engine), PTC claims companies can improve their publishing processes and gain significant competitive advantage through improved time-to-market.

Other PLM vendors also have new products available. Siemens, for example, recently released the latest version of Solid Edge that includes ‘synchronous technology’. The company describes the breakthrough as ‘history-free, feature-based modelling’.

With most parametric feature-based CAD programs, the parameters of the features in a design are tracked in a history tree and stored in the order in which the user creates them.

As users make design changes to the model, an algorithm in the program recalculates each feature in the order they appear in the history tree. The problem with this is that changes in the early part of the tree can cause features in the later part of the tree to fail.

‘Synchronous technology breaks through the architectural barrier inherent in a history-based modelling system,’ said Ken Versprille, PLM research director, CPDA.

‘Its ability to recognise current geometry conditions and localise dependencies in real-time, allows synchronous technology to solve model changes without the typical replay of the full construction history from the point of edit,’ he added.

‘Depending on model complexity and how far back in the history that edit occurs, users will see dramatic performance gains. A 100 times speed improvement could be a conservative estimate.’