Several years ago, Altair OptiStruct™ breathed life back into a stalled million-dollar cost savings project at a manufacturer of heating, ventilation, and air conditioning (HVAC) units. The project’s mass reduction goal for an HVAC structural component seemed at odds with maintaining stringent safety factor requirements, putting its whole cost justification in jeopardy. The project team turned to OptiStruct for a radical component redesign that not only resolved this conflict, but also expanded the business case.
This case study offers insights on how OptiStruct can impact projects by shifting work from established norms to simulation-driven design, and how engineering analysts using optimization can stand to benefit.
Situation: A project team’s critical path obstacle
HVAC units have a product lifespan that often lasts years, if not decades. This particular model had launched long before, but continual engineering work was still dedicated to incrementally improving its efficiency and reducing its cost. Project teams convened each year and committed to a certain percent of cost-out from the HVAC unit.
Engineers experienced with this HVAC unit expected that hundreds of thousands of dollars could be saved annually by redesigning a plastic structural component. Since the component was produced in such high volumes, finding a way to save even a modest amount of plastic per part could help the manufacturer meet its cost-out target for the year.
A project was kicked off to investigate, but the team was struggling to produce a reduced-mass design that could withstand the same loads as before. Compromising on the structural component’s safety factor was unacceptable and would have been a dealbreaker for the project.
There were also other risks to the project’s business case, such as which specific plastic material to select, or qualifying a supplier to produce the eventual redesigned part. Each posed questions that could increase or decrease the size of the business case. But none of these questions were worth considering until a viable new design had been validated by the engineers. This placed the redesign task squarely on the project’s critical path, forcing a binary outcome for the project team—fail to meet this year’s cost-out target, or find a viable design and move to the next project phase.
Result: Optimization’s compounding benefits
The project team shifted focus away from guess and test development, where a designer had been producing a fully finished computer-aided design (CAD) model, handing it off to an engineering analyst for finite element analysis (FEA) tests, and repeating the cycle until achieving acceptable results. Instead, they adopted a new simulation-driven design workflow with Altair’s software solutions, since no other software vendor offered this capability.
Here, a designer produced only a simplified CAD model whose details included just the structural mounting points to other components in the HVAC unit, resembling a shell. Filling the shell was the design space—a solid, featureless block within which the eventual design might be found. The engineering analyst imported this model into Altair HyperMesh™ and applied the same loads and boundary conditions as before. Then OptiStruct was tasked with finding a design on its own that maximized the strength of this component while still meeting a given weight reduction constraint. Additional constraints for manufacturability were added to ensure the design could be mass-produced.
The results were striking.
OptiStruct had found a design that exceeded the project team’s safety factor goals, prompting them to re-run the optimization with an even greater weight reduction constraint. Completing the simulation-driven design workflow, the designer then used OptiStruct’s output as a guide for creating the new detailed CAD model. The engineers were surprised that an answer to this critical path question had been found so quickly.
Now the project was back on track, and with an expanded business case to well over a million dollars in annual material cost savings. The sustainability benefits of using OptiStruct were also substantial; the amount of raw plastic avoided in the supply chain was equivalent to swimming pools’ worth of material each year. Months later, the project team was recognized by the manufacturer’s chief executives for these achievements and for pioneering simulation-driven design at the company.
How to look for optimization opportunities: Find the right metric
How did OptiStruct make the leap from an engineering tool to something that delivered transformative business impact? It may be the Swiss Army knife of structural optimization tools, but not every application can make waves outside of engineering groups. The key for this HVAC cost savings application was the metric by which OptiStruct was judged—mass reduction.
This metric tied directly back to a critical path task on the project. Even though the time savings from the new simulation-driven design workflow was an added benefit, finding an answer any faster on whether a redesign was possible wouldn’t have been enough on its own to get the project back on track.
Different projects call for different optimization applications. New product development projects are driven mainly by speed, where manufacturers want to cut down on design cycles as much as possible in their race to launch the product. This is where simulation-driven design can save months of development time by eliminating guesswork between the design, engineering, and production teams. Ongoing lifecycle projects are less motivated by speed, but instead by predictable cost-cutting as the manufacturer slowly discounts prices for its aging product.
Optimization is inherently multi-disciplinary, giving the engineering analyst a chance to work with project leaders and make an impact beyond his or her team. And tailoring OptiStruct’s many applications to the right business case metrics is his or her moment to shine during project work.
- Data Analytics Delivers Competitive Edge, On and Off the Track - December 3, 2020
- Design and Manufacturing of Injection Molded Products - December 3, 2020
- Fujitsu Deploys Arm Processors for Efficient HPC - November 19, 2020