Last year Tesla CEO Elon Musk rattled automotive circles with his suggestion that he would replace assembly-line manufacturing with a more modular, “unboxed” approach to producing electric vehicles (EVs). This left many auto executives wringing their hands over whether to follow or help lead this bold departure from the 111-year-old manufacturing process that came to define the industry.

But legacy automakers have a fine balancing act to maintain. Unlike Musk, they make both EVs and vehicles powered by internal combustion engines (ICE). The majority of production will most likely remain ICE autos for the next 10 to 15 years, especially in the United States where the speed of adoption of EVs is less clear. While reinventing assembly lines makes some sense for EV makers trying to push for a lower price point by building a more cost-competitive vehicle, it would be an immense expense for legacy automakers faced with switching over the production of tens of millions of ICE vehicles to maintain consistent standards across their global networks.

Does that leave legacy automakers without options to achieve a performance transformation around the assembly line? Not at all. The potential scope of a revolutionary solution doesn’t mean legacy car manufacturers should give up this opportunity to rethink the assembly-line process. While the industry likes to tout the “revolution” taking off in EVs and eventually autonomous vehicles, “evolutions” produce more long-lasting and sustainable adaptations than revolutions, which are often prone to a series of advances and retreats. What’s the expression? It’s a marathon, not a sprint, and the major global producers need to be looking for those adaptations that will produce the most return on investment.

The assembly line evolution — embracing gigacasting for cost efficiency

In general, assembly lines inject a good deal of rigidity into the manufacturing process and the need for large workforces. Both can add costs. The starting point for the legacy car companies needs to be identifying the aspects of assembly-line manufacturing most in need of improvement and those that will deliver the biggest return on investment in terms of performance and costs savings. Then, such evolutionary transformations should be executed in small steps until companies find the best fit for their needs to avoid false starts and wasted investment.

Still, traditional manufacturers need to acknowledge the inevitability of significantly larger EV production down the road and prepare for it. One way would be to give a closer look at gigacasting — the technological breakthrough that enabled Musk to contemplate the unboxed process. Gigacasting involves creating sections of an auto using large molds.

In theory, gigacasting should result in lower per unit costs of manufacturing by eliminating the welding of multiple body parts and the workforce that welds them. Here some proof of concept has been achieved with Chinese EV producers already moving forward with the gigacasting process, and car giants like Toyota are also launching pilots.

Manufacturing digitization on the rise, just not fast enough

But even before looking at such a radically different process, legacy automakers need to review innovations that they may have only dabbled with in the past, such as smart automation. This would include technologies such as automated guided vehicles (AGVs), co-bots, predictive maintenance, and vision systems. For instance, significantly more use of AGVs could start to address the rigidity of the assembly line process by potentially eliminating some of the infrastructure.

More smart automation would address a persistent problem automakers have wrestled with: Labor productivity has been relatively flat year over year, according to The Harbour Report® data. Given that continuous improvement must be the foundational mindset of any lean organization, labor productivity and smart automation should be an area of focus for companies looking to achieve any degree of performance transformation.

Digital manufacturing can deliver improvements in manufacturing excellence, process, and quality as well as step changes in performance that lead to bigger savings and flexibility. Here, automakers are already significantly increasing their commitment, with manufacturing digitization expected to provide a 10% to 25% performance improvements in labor productivity, lower maintenance costs, and overall equipment effectiveness and other productivity metrics over the next one to three years.

Adoption of digital technologies is expected to double between 2020 and 2025, as digital manufacturing is increasingly considered a strategic enabler. Not only will this address sluggish productivity gains but also provide car companies with more agility in areas like inventory reduction, cost containment, and forecast accuracy, shorter time-to-market, and increased sustainability.

While automakers have made big strides over the past five years, they are still too cautious on the tech that would bring about bigger transformations and potentially bigger savings. The anxiety over the viability of unboxed process and gigacasting should at least translate into greater progress in applying the more tested tech.

Cutting complexity in automotive manufacturing

Another focus area should be better collaboration upstream with research and development and manufacturability. Over the last decade, car companies have had to deal with increased manufacturing complexity, with significantly more parts per vehicle to provide the options customers demand — a significant contributor to the lack of labor productivity improvements. Today, there are 17% more parts per vehicle, on average globally, versus 10 years ago, The Harbour Report® shows, which is partly the cause of the flat productivity. The additional parts have translated into a 26% increase in logistics labor hours per unit over that same decade.

Designing new programs with manufacturability and assembly in mind can increase performance, reduce cost, and uphold quality. For instance, Rivian’s second generation R1 vehicles feature an entirely new electrical architecture and computing platform, which cuts the number of electronic control units (ECUs) to 7 from 17. Reducing complexity can enable auto plants to reduce labor hours and costs as fewer work elements and workstations are needed to install the ECUs and wire harnesses.

None of these changes really constitute a revolution but could be expected to produce the kind of cost reductions and flexibility more dramatic performance transformations are known for. Following an evolutionary path allows executives the time and testing to choose the transformation that is the best fit for their needs, which leads to a better overall investment of capital and effort. Remember, the tortoise wins the race in the end.