Interoperability problems can appear across the entire supply chain, but one of the main areas of risk that has to be addressed is when people try to read data from one CAD system into another. It is in many respects one of the more serious and risk-laden aspects of the engineering process with issues of data validation and checking needing to be considered.
According to Stuart Thurlby, managing director of the data exchange specialist Theorem Solutions: "As a problem, interoperability is becoming acute as more key manufacturing data is incorporated within 3D CAD models."
Theorem Solutions, which is based in the UK, has been working to address this problem since the early 1990s, providing a range of advanced data translation products that reduce the manpower and time spent preparing and processing data.
"What manufacturers face," explains Thurlby, "is best summed up by what we see in the automotive sector. While the badge on the front of a car represents the history of the company and the technology associated with the brand, around 65% of each car is sourced and produced by companies from within the supply chain, not the OEM itself. That means each OEM has to collaborate with a long supply chain made up of Tier 1 and 2 suppliers sharing extensive engineering design data. And what's true of the automotive space is true of every other industry.
"Now, collaboration works well if the parties concerned have identical systems, but that's not the case in most instances," he continues. "More often than not, companies will have developed their own systems over time which means that interoperability problems will appear in many different places. When users are trying to read data from one CAD system into another, it is often the case that even different versions of the same CAD system are unable to share models."
This is where Theorem's solutions look to help. The different ways in which systems work and the different tolerances they apply can result in a perfectly valid translation producing a model that is not quite the same as in the pre-translated source model. Where the CAD systems have entirely different kernels, the possibility exists that there may be even greater differences.
"Our applications are designed so that CAD systems will see the same thing," explains Thurlby.
While industry standards exist – ISO10303, known informally as STEP (Standard for the Exchange of Product model data), is trying to solve the problem of CAD file interchangeability – there is a tendency, according to Thurlby, for them to 'always be in arrears'. "CAD changes year on year, while standards take much longer to formalise and then implement. What Theorem looks to do is provide a much richer set of content between different applications."
Data translation can take up much more of an engineer's time and many now use visualisation techniques to inspect the model and drawings for any obvious flaws and to run a system check to see if the CAD system believes the model is correct.
The growth in visualisation has meant that a 3D model was often accompanied by a 2D drawing. Today, people just send the 3D data and, as a result, both validation and the process of checking files is even more important because of the different CAD systems being used.
"The richer the content, the greater the chance of compounding problems," says Thurlby.
"Model based definition data has become more important and people are looking to use CAD file content in a far richer way – they want to be able to include material, finish and costing details. Users of CAD files want to be able to use all the functionality that is being made available to them.
"While I don't think the design process has changed, the content and richness that are available has. But when you think about CAD files details on geometry and product structure, while helpful to a design engineer, they are not necessarily of interest when it comes to the manufacturing process or when it comes to inspection. For that you'll need key dimensions, finish information and so on. We need to open up access to these files. The richer the data the more people can use it and the more transparent the supply chain."
As a result, the ability to share data with non CAD users is becoming more important, especially if you want to reduce ambiguity across the design process, according to Thurlby.
While PDF files are one of the most useful file formats, that wasn't the case when it came to embedding 3D models and images within them. Theorem has sought to address this problem with the recent roll out of what it calls its 3D PDF publisher.
"This new software Publish 3D has many of the features that currently exist in Theorem's Process Manager Suite of data exchange automation tools. It will allow all manner of users to create documents that contain 3D data that can be directly published from native CAD data," explains Thurlby. "Using a 3D PDF plugin for Adobe Acrobat Reader, you will be able to view the files without having to buy any additional software or having to interrupt the CAD user.
"Most employees in the supply chain cannot open CAD documents, so we wanted to create something that people could open no matter what, so that everyone could benefit," he says.
Theorem's 3D PDF documents are intended to extend the use of 3D design data beyond the boundaries of mainstream engineering and to increase levels of collaboration up and down the supply chain.
"3D PDF opens up real opportunities for sharing design intent within organisations and through the supply and distribution chains. The working PDF document can be annotated, shared and additional media embedded including text, PowerPoint files, spreadsheets, AVI movies and hyperlinks to additional online information."
Thurlby believes the product will bring benefits in terms of both greater openness and speed. "It will mean the better understanding of product information. Rather than text with a 2D PDF drawing, all users will have access to a 3D representation which will provide a level of detail and product understanding that just hasn't been available.
"It removes any ambiguity; speeds the production and purchasing process and improves overall quality. More importantly, it is accessible to anyone with Adobe Acrobat, there's no need for special files or specialist tools to read the documents."
