Rooster's Revenge

The curse of technical people, I am convinced, is they are too technical in situations where detail does not matter. They have an obsession with covering every minute detail when a high level concept is all that is needed.

Case in point: advanced feasibility of metal stampings.

Here is a situation where the product geometry, material type, and material thickness is far from frozen. “Frozen” is an automotive term for final designs that are released for production. Final, in this market, means “design intent will most likely change unless hell freezes over”.

At this point in the product development process, someone somewhere is simply looking for feasibility. Not validation.

The formability and proposed process is all we are looking for here. Is it a crash form or a form or a multi-stage draw?

Will it run in a progressive die or transfer?

Hell, even a rough blank size and budgetary tool cost may be required as well. Rough does not mean down to two place decimals on dimensions. Budgetary does not mean down to plus or minus 2 cents.

And that is my two cents: getting down to the level of detail of sourcing blank suppliers, getting 57 people to sign-off on a process that stands a 90% chance of never turning into a job for a product design that stands a 99.9% chance changing somehow someway to make all the advanced work a complete waste of time.

Focus on what matters. Don’t go overboard.

I see alot of shops, with good intentions, performing engineering in the wrong sequence.

They process a job. They design the dies. Then, they run formability analysis. For the first time.

The first time formability simulation is run is called feasibility.

The question here is: will it work?

In other words, is the product design, material specification, and addendum feasible for production stamping?

Will it work?

Validation, on the other hand, is the act of making sure the die design intent is functional for production stamping.

The question validation must answer is: does it work?

There is a fundamentally practical difference between feasibility and validation. Feasibility is performed long before hundreds of hours of die design work is started.

Validation is a final check on the tools and process for the die design. Forces, travels, basic die mechanics (along with refined formability simulation analysis, of course).

Asking the feasibility question just days before the die shop will start making chips is the wrong time.

What if the development does not work?

What if the tool architecture does not work?

I will tell you what happens: redesign.

Formability must be done ahead of die design. It is that simple.

Go ahead and run simulation again at the end for validation if you like. But running it for the first time prior to die build, in most cases, will prove to be a time and money disaster.

My dear friend Eric Kam does a great job conveying stamping simulation “geek speak” with his blog.

There has been much talk recently in the industry and online about forming simulation feasibility versus validation.

Reams of paper documents and terabytes of data have been generated by the PhD crowd about this topic.

From the trenches, let me boil it down to its core.

Simply stated, think of feasibility as “make it work”.

Validation can then be defined as “does it work”.

Plain and simple …