Why Simulation Should Drive Product Development

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By Dr. Jason Lemon
Founder and Chairman
International TechneGroup Incorporated

When it comes to developing new products, conventional methods are too costly, time-consuming, and inefficient for manufacturers to compete in today's turbulent economy. Throughout this cycle, organizations race to create a design so they can analyze, build, and test physical prototypes to confirm intended product functional performance. As a result, many changes occur along the way, so development schedules slip, costs skyrocket, and products often fall short of market and business requirements --- increasing the risk of customer dissatisfaction and/or recalls.

A new simulation-driven approach to product development represents a significant cultural change --- a paradigm shift. Now some companies are performing simulation first in the concept stage to explore alternatives, spot flaws, and optimize product performance before the detailed design - let alone a physical prototype - is created. The process allows important decisions to be made on functionality, geometry and materials early in the cycle based on simulation results.

A wide range of technologies are used in simulation-driven product development including multi-physics simulations, electromagnetics, fluid dynamics, structural finite element analyses, fatigue and failure analyses, acoustic predictions and design optimization. Using these and other types of analysis tools in upfront development, simulation guides the direction of the design to optimally satisfy performance, structural integrity, reliability, durability, cost and other requirements. Most importantly, simulation guides critical trade-off decisions to balance competing product objectives; reliability, cost and weight requirements, as an example. Usually hundreds of concept alternatives are evaluated before detailed design is begun.

The simulation-driven process relies heavily on setting targets for overall product requirements. Targets are cascaded from system to sub-systems and assemblies to individual components. In automobile design, for example, dynamic motions that characterize ride, harshness and vibration targets are translated into resulting forces and displacements in the vehicle suspension, which in turn are used to establish design targets for shock absorbers and individual bushings and connectors. The product can then be designed from the component level up to satisfy these various levels of requirements with much greater assurance of overall product success.

Hardware prototypes then are built and tested primarily to validate these virtual prototypes. Of course, some changes will still occur at the physical testing phases, but the number of costly and time-consuming changes is reduced by orders of magnitude. Likewise risk/recall programs are substantially less. In this way, designs satisfy engineering and business objectives much more closely than those developed using the old design-analyze-build-test cycle.

Measurable Benefits
For over two decades, International TechneGroup Incorporated (ITI) has helped hundreds of clients implement simulation-driven processes, which we call more specifically Systems Engineering/Analysis Lead Design (SE/ALD�).

• Using SE/ALD, an aircraft engine manufacturer evaluated more than 1,000 concept alternatives using simulation-driven design and got to market a full year before their closest competitor.
• An agricultural tractor manufacturer developed a new product in half the time of conventional methods at 30% cost reduction, with the tractor setting best-in-class performance standards in noise reduction and turning radius.
• On its initial simulation-driven development program, a power tool manufacturer produced a cordless driver that increases market share 63%. The methodology was applied to other tool programs with similar results and is today being implemented throughout the company.

Similar results are being documented by those who manufacturer everything from automobiles and printers to home appliances, lawn and garden equipment, office furniture, hard disk drives and more.

In these types of applications, most of the benefit of simulation-driven development is derived from the fewer number of engineering changes made after detail design begins compared to conventional methods. Building multiple physical prototypes is rarely practical or cost effective. Conversely, validated virtual models representing a number of design alternatives can be modified, analyzed and evaluated to lead design decisions at a fraction of the time and cost. With simulation-driven methods, overall design costs are cut because changes in the latter stages are reduced with successful products assured at the beginning of detailed design. An important measure in simulation-driven development, therefore, is the number and cost of design changes, as shown in Figure 1.

Figure 1: Engineering Changes & Associated Costs

Looking at a typical company using the traditional design-analyze-build-test approach, the cost of design change and the amount of money spent in the series of prototypes are enormous. To lower design change costs and the shape of the curve somewhat, many companies today use digital engineering, where CAD models replace engineering paper drawings and some level of computer analysis is performed after designs are created. The greatest impact is made with SE/ALD simulation-driven development in radically lowering the number of design changes later in development by concentrating engineering efforts upfront in the process. Thus, companies must focus more resources earlier in the process, with as much as two-thirds of their engineering budget spent before detailed design begins.

Figure 2: Return on Investment for Upfront Engineering

As shown in Figure 2, this increase in upfront simulation can result in significant added return on investment (ROI) and improvements in breakeven production volumes. But a paradigm shift in top management thinking is critical in providing sufficient funding early enough in the program.

Implementing the Process
Effective implementation of simulation-driven development begins with establishing a baseline consisting of your own existing product, or that of one or more competitors. Products are tested to build a quantitative knowledge base of information on product behavior that will be critical in correlating the analytical and physical, and in providing empirical data where computer modeling is impractical. In this case, hybrid models are built combining virtual models and test data to accurately represent the system. Once this baseline is established, various components and subsystems can be modified to evaluate multiple alternatives before beginning the detailed design process.

An important aspect of establishing the baseline is Customer Usage Profiling (CUP). In a typical CUP program, products fitted with instrumentation and data-collection gauges are provided to customers for use over an extended period of time. This indicates, often with surprising results, how products are actually used, and abused, in the real world. For example, the armrest in a car is designed to support the weight of an arm, but will it safely support the weight of a child climbing into the back seat or a bowling ball tossed into the car? How much force can be applied before a knob being turned in the wrong direction breaks? Is the current mirror on the motorcycle over-designed? Can a lighter, cheaper material be substituted? CUP saves warranty, liability, and material costs by making sure components are neither under nor over designed.

Customer usage profiling and related load and duty cycle definitions serve as a foundation for overall product target setting, where goals for overall performance and functionality are established. Targets are based on CUP requirements, competitive benchmarking, and product features deemed necessary to strengthen market share and brand image. These product system targets are then cascaded to bring the dynamic loading and duty cycles to individual parts, allowing engineers to evaluate reliability and durability and achieve very good first design of the geometry and material at the component level.

With these increased levels of simulation being performed in meeting the various targets, orders of magnitude more data and document files are generated than in the more traditional development processes. The resulting need for up-front data management is critical in terms of information sharing, data quality, security, and collaborative capabilities via the Internet. Thus, companies getting into simulation-driven development need to define requirements and build the information platforms they need for this advanced work.

Embracing Change
The message is simple and painfully clear --- product development organizations not taking steps in the direction of simulation-driven product development are behind and falling further back every day. The key is an understanding of the enormous return on investment and a willingness to embrace change. Development leadership is not achieved from a "leap of faith" but rather by adopting tried and true simulation-driven development methodologies. For many companies, implementing such an approach could mean strengthening their position in brutal markets that otherwise will eat them alive.