Why would anyone in manufacturing industry not use direct modeling CAD tools? (Or any design discipline, for that matter?) I was thinking about this and how there are still so many shops unaware of the CAD “alternatives,” or they still struggle to open their blinders. After all, they are already using a mainstream history-based solution and believe it to be the best and only solution. But is it?
So this got me to thinking about the evolution of CAD tools for manufacturing, and how the “new” generation of Direct CAD is still relatively unknown. How many people still do not realize what a highly productive alternative or even complement to the current CAD products Direct CAD can be. In particular I wonder how many contract manufacturing firms have considered the effect on overall performance and bottom line by not having direct CAD in their arsenal.
A major reason manufacturers should consider Direct CAD is how we conceive and create designs. Not that long ago, pencil and paper (or drafting) was the primary method of capturing such design intent. (And it still is the primary method for many!) Conceptualizing and immediately putting ideas down on paper offered a very natural way to visualize and create our designs. This is a pretty straight forward process in that we imagine, and then simply draw our ideas - depending on our skill - to express ideas in the form of blue prints. Of course this evolved into electronic layout drawings or 2D CAD which gave us a new ability to cleanly express our ideas (no need for good artistic skills), and perhaps, more importantly, it gave us quicker ways to edit/recreate design intent – and thus, the first “Direct CAD” modeling was born.
This ability to capture our thoughts easily in electronic form was in fact “direct” since we could interact directly with the geometry by deleting, trimming, breaking, moving, etc. Eventually the new generation of direct dynamic editing tools allowed us to “physically” work with complex 3D design content – the ideal approach for manufacturers since it is the most intuitive approach. This is particularly important given that manufacturing is downstream from product design and must produce tooling (and products) with never-ending pressure to do so for less money and time.
But early on, CAD technology diverged into another modeling method: history-based feature modeling. This was not just a disruption to the current process, but it created a veritable storm in our creative process, not necessarily a good storm. It came about when PTC finally launched Pro/Engineer, the first commercial history-based feature CAD system circa 1988. The world was understandably awed by the seeming magic of being able to edit 3D designs without tediously having to break apart and reconstruct complex geometry – particularly 3D geometry.
While direct geometry modeling was still evolving based on the work of a few pioneers (HP’s Solid Designer, CADKEY, etc.) no one could stem the rush to history-based methods once it got rolling. And so from a market share view, the yet unfulfilled promise of Direct CAD essentially went into hibernation for a number of years.
From the software vendor’s side, we probably should have considered how much we were offering in the way of improved tools to create, engineer and manufacture products. For the most part everyone blindly charged like a buffalo stampede down the path of “history” modeling, all attempting to offer similar tools, yet with all the same burdensome, costly restrictions…
Anyway history is history (no pun intended) and as a result, I am convinced we lost significant flexibility which in turn has had significant impact on how productive we are – particularly from a manufacturing view. And how much has this cost us?
Meanwhile the next big “change” in the CAD industry primarily involved lowering the cost of the software and offering it on relatively inexpensive PC’s – while this was a very effective business model it further put the awareness and promise of direct modeling in the background.
But did we really understand how much we lost by unilaterally embracing what is arguably a very unnatural way to work with CAD? To achieve the “magic” of editing complex 3D models using history-based methods, manufacturing users had to try and work with overly complex, order-dependent, formulaic, and rigid constraint-based files to build tooling assemblies and fixtures – a difficult, inflexible process at best. Even worse, this method further locked users into fewer and fewer vendors with less opportunity to effectively share data.
Perhaps the biggest downside of this approach was the lack of effective ways to manipulate files from different CAD systems (aka “dumb” geometry) without essentially rebuilding designs from scratch. This has proven to be much too costly whether trying to manage up-front design change, or more importantly for those manufacturers dependent on this history-constrained data. So what were their options: purchase a number of different CAD systems, then hire and maintain all the staff/expertise to operate these different CAD systems? Clearly not effective either. And the notion that if most of my customer files come in one format, then I simply need to use the same system is equally false. While the vendors love, and still very much promote this idea, it is also bad for number of reasons – it prevents the “data openness” needed for manufacturers to take on more types of work to become more productive and profitable.
Before all the champions of history-based CAD come at me with your torches and pitchforks, telling me how your superior expertise makes you masters of your parametric universe (and BTW, I consider myself as having been such an expert once), tell me how effective are you at handling models created by co-workers, let alone projects from outside your company? From my own experience (and for those willing to admit it) it can be challenging to manage even your own designs, particularly as the complexity grows – debugging history, constraint and mate errors often lead us to throw up our hands and start projects over. Again, how much lost time and productivity has this cost all of us?
The good news is since true Direct CAD works explicitly on the geometry and does not rely on any history order dependencies for recognizing and making changes, it alone offers respite from the tedious drudgery of history-based modeling’s arcane work methods. In fact, it is the most natural transition from the aforementioned pencil and paper. Direct CAD alone offers the industry the most open and flexible toolset to work with different CAD formats, and does so using physically intuitive tools that truly save considerable time – this is a gold mine for manufacturing.