Simulation: promise vs. reality

Engineering simulation can cut manufacturing costs and time but working out a favourable ROI is one of the technology's many challenges, writes Stephanie McDonald.

PARTLY art but largely sci ence, simulation allows users to manipulate 2D and 3D CAD models to simulate the physics of how a structure or a process might form in a virtual/digital environment.

But like most technology, it is not without its challenges — working out a favourable ROI, up-skilling employees and decid ing how much of the design process simulation can replace.

The main benefit of simulation is it reduces costs and time as it lowers the number of physical prototypes required. It also reduces errors in the design process.

Vernon McKenzie, director at EnDuraSim, says the cost benefit of simulation for high value products such as airplanes and spaceships is obvious: situations where prototypes are extremely costly or not possible.

“When working out the cost benefits of lower value products such as small mechanical prod ucts and structural products and process, the same ROI is yielded. The only difference is the model and equation are smaller,” he told Manufacturers’ Monthly.

“The cost benefit equation has several inputs. For example, com paring the cost of a prototype (including material and labour costs) and the cost of revising the physical prototype if an error is found to the cost of running numerous iterations in simula tion software.

“Even though the simulation might not get it exactly right because it’s fairly complex physics, it gives users more insight into what parts of the product is doing the work when the test is performed.”

He believes the cost of the software and computing power required is relatively low. The main financial expense is hiring either a consultant to carry out and analyse simulation results or employing or training an engineer in-house to carry out those tasks.

According to McKenzie, it can take up to 18 months for a per son to become completely com petent in simulation capabilities.

“For us, that’s our biggest con cern for customers getting value for money — whether they should be getting us to consult or whether they should be developing this expertise in- house and making the effort to do this sort of work them selves,” McKenzie said.

He believes companies should be developing the expertise in- house, particularly if engineer ing design makes up a large part of their company and where intellectual property is at stake.

“I don’t believe they should be outsourcing the simulation aspect of that. Rather they should make the decision that this is technology they should be developing expertise in and using the advantages of simula tion within their own organisa tion,” McKenzie said.

However, he freely admits the cost benefits may not always be immediate or even quantifiable.

Counting the costs

Graeme Klee, senior design at GRG Consulting Engineers, says his company has been using sim ulation software for over two years for the analysis of steel structures, tank analysis, struc tural connections and mechani cal components.

“But at this point in time, I do not believe there has been signif icant cost savings,” he said.

“However, we do not use the software package on a day-to-day basis and as such, the biggest challenge due to the lack of reg ular use is it is difficult to be conversant with the diversities of the software and the various options available in its dialogue boxes.

“Nevertheless, the software has broadened GRG’s scope to a wider range of more com plex design projects that can be undertaken, therefore exposing GRG to a broader engineering market.”

According to McKenzie, a big advantage of simulation is it pro vides insight into several aspects of product development. “Which parts didn’t work, but also aspects which did work.

“This allows engineers to not only assess errors, but also to look at whether areas have been over designed or where they could be better optimised. These insights may not be gleaned from physical tests.”

McKenzie says the key for smaller companies making the most of simulation comes back to expertise and whether they choose to develop it in-house or use consulting companies.

“That decision is not a trivial decision because it involves either a high cost in terms of a person they’re going to employ and how much time that person will be used in that particular area of their expertise, or if they develop up a person, how long is that going to take,” he said.

Simulation has theoretically meant prototypes aren’t required, but McKenzie is adamant this process should not be entirely eliminated.

He recommends a physical testing program to calibrate simulation processes to provide external validation of simulation results.

Otherwise, the simulation will work on a user putting in all information correctly, which may not always occur. Without checking simulation results, the risk of errors at the end increases.

“The connection between the practical, real world conditions and how the product operates needs to be preserved, otherwise there is that risk that the prod uct is not going to be as good as it needs to be.

“We hope that organisations that are sensible enough to invest in digital simulation technology take heed of our mes sage, which is — don’t completely disconnect this from the physical world.”