Today's vehicles are increasingly complex. Some cars, in fact, have over 100 electronic control units (ECUs) to support advanced driver assistance system (ADAS) functions and other features that rely on sensor input, like parking assistance and power steering.

Adding to the complexity, present-day vehicles feature multiple communication buses with directly wired sensors, actuators, lights, and controls.

In the past, a vehicle's software was simpler to define and design. The software often ran from a single computer, with a dedicated wire connected directly to a sensor and an actuator.

Today most of the changes occurring in the vehicle are happening via software, according to Brett Hillhouse, Global Automotive Leader, AI Applications, at IBM this month.

"Now all the software is interacting on these networks where everything is being shared," said Hillhouse, in a live Tech Briefs presentation titled Transforming Automotive Engineering by Tackling Complexity.

The meshing of software and mechanics requires a collaboration between two engineering teams that perhaps, in the past, could manage to remain separate.

"Where software and electrical engineering is converging is the most complex place, and it's also one that can use additional attention and focus," said Hillhouse.

So, in this increasingly complex environment, what should these mechanical and software engineering teams have at the top of their to-do list?

Two Tech Briefs readers had the following questions for Hillhouse. Read his edited responses below.

"Are new requirements and regulations for over the air updates impacting vehicle architecture and complexity?"

Brett Hillhouse: We're seeing new regulatory items popping up, like WP.29,  and it is adding a new dimension to the systems architecture. It's truly the "system of systems" architecture, which includes some of the offboard capabilities found in the cloud, from a connected perspective.

There's also complexity on the testing side. I have to test against the various configurations before I can give an over-the-air (OTA) update back into the vehicle.

We're working with clients both on trying to understand the regulation, help them manage the compliance, and then understand how the two tool chains need to work together better to support the OTA environment. It's certainly high of mind.

"With increasing levels of complexity, how does the team prioritize which items need to be addressed?"

Brett Hillhouse: This is a good engineering question.

First of all, I think in most cases, everything has to be addressed. so it's about the prioritization: What do you spend your time on? And a lot of the process that the engineering teams in automotive go through is certainly in prioritizing items that they have to get right: automotive safety integration levels (ASIL ), the whole ISO 26262 process .

The other important priority, I'd argue, is what is new: the new functionality that you think is going to be the most difficult and require the most reasoning and effort. The functionality that typically needs some more iteration.

When we just are looking at it from an engineering complexity perspective, those things that are new and complex, and that are cutting across multiple different domain or different ECUs, or different software functions, those are the ones that we typically see our clients clearly prioritizing and trying to get right before they get to system tests.

What are your automotive test questions? Share them below.