Virtual Realities – Product Verification and Validation
Compressing the schedule
The product development cycle has changed quite a bit in the last decade. Not too long ago, the vast majority of iterative design refinement took place in the prototype stage. Physical prototypes were developed, tested and analyzed. The resulting data indicated how the design should be improved, and another round of prototyping began.
The big advantage of this approach is a firm grounding in reality. It involves real products interacting with actual operating environments and conditions. The downside is that it is both time-consuming and expensive. Think of the resources required to build a complete prototype of a new car, instrument it, drive it around the proving ground, and then evaluate the data. The same factors are at work whether your area of expertise is aircraft, consumer packaged goods, sports equipment, medical devices, or anything else.
Modern development cycles have become so compressed that they can no longer accommodate the full prototyping process. Materials are too complex. The relationships between constituent parts and subsystems are too interconnected. The goals engineers are trying to achieve — from lower costs to higher efficiency to game-changing innovation — are too important. And the push to bring new offerings to market faster than the competition can’t be understated.
In other words, by the time a full prototype is ready to test, it’s already too late to address major design changes without compromising the budget or the schedule.
Checking and rechecking
All of these factors have elevated the importance of verification and validation processes. Powered by computer aided engineering (CAE) software, these processes enable engineers to understand and resolve potential design vulnerabilities much earlier in the process and typically for lower costs. More and more, designers and CAE analysts are working together to understand the characteristics and behaviors of products, anticipate performance issues, and pinpoint ways to improve the design.
Verification and validation are essential because they are the first line of defense against errors that trigger delays in bringing new products to market, or worse, releasing products that do not meet performance requirements and result in warranty costs, recalls and reputational damage.
To be clear, verification and validation are related but separate processes. Verification ensures that the design meets the initial requirements, while validation explores whether the design performs as expected, and if not, how it failed.
These processes depend on and reinforce each other. If the design is not verified, the validation will be meaningless. Similarly, if the validation is flawed, ensuing design changes may prevent the eventual product from performing as expected.
Blurring the lines
The extent to which verification and validation are related speaks to the “blurring of the lines” between the roles of designers and CAE analysts. Originally, verification was the domain of designers while validation was reserved exclusively for analysts. One specialized in innovation while the other focused on mathematical precision.
Today, the roles are not as clearly delineated. Because the simulation tools involved in both stages have become significantly more powerful and easier to use, designers and analysts are more frequently collaborating during verification and validation. Designers are using analytical models to improve product designs sooner rather than later, while analysts are not simply analyzing failure modes but providing specific recommendations for how the design should be changed in response.
Where there were once two parallel paths, now there is a spectrum of experience. Some designers move further into CAE analyst territory than others, and some analysts will venture further into the design world.
The key takeaway is understanding what each person brings to the table. For designers, it’s a big-picture understanding of the purpose of the product — what inspired the design and why it’s important. For CAE analysts, it’s a deeper knowledge of the calculations involved in finite element analysis (FEA) and computational fluid dynamics (CFD) tools — what the simulations show and what specific issues must be addressed.
Reducing cost and risk
When verification and validation work hand in hand, the results can have a significant impact on some of the overarching concerns all manufacturers share.
Not only do these processes help improve designs earlier and for lower costs, they enhance how prototypes are tested. Requirements for mechanical and virtual tests are often developed according to a similar cycle as the product itself, so there is a risk of the test parameters being out of synch with the current iteration of the design. Faster verification and validation, accelerated by simulation tools, helps keep design and test teams in alignment.
Prototyping costs can be dramatically reduced through effective verification and validation, simply because the eventual prototype is much closer to the final product than was previously possible. This means fewer rounds of mechanical testing and a much lower risk of discovering design problems that throw off the launch date.
Most critically, verification and validation help reduce the incidence of all the negative outcomes manufacturers seek to avoid: warranty costs, recalls and poor customer satisfaction. Two of the most frequent causes are design deficiencies and variations in manufacturing. Together with rigorous physical testing, verification and validation result in more reliable designs, stronger performance in real-world conditions and a better understanding of which processing variables must be monitored and controlled to avoid quality issues.