Eco-design of Complex Systems: The Importance of Integrating LCA and Systems Engineering

On June 5th and 6th, the festival Et Demain? (And Tomorrow?) took place in Nantes, where I had the great pleasure and honor to participate.

This festival, organized by La Cantine Numérique in Nantes (known for the famous Web2Day), aimed to be an event for "professionals looking to evolve their practices, their professions, their ways of communicating, and working to shape a sustainable future." The goal was achieved!

One of the innovations was the collaboration with EMC2, the European manufacturing technology cluster, based in Nantes, to whom La Cantine Numérique entrusted an “Industry” track. It was in this context that I was invited to speak at the round table “Disrupting Industries for a Sustainable Future” moderated by Landry Chiron of EMC2, alongside Julie Vaudour, Deputy Director R&T of Daher, and Franck Halary, a researcher at INSERM.

 

The goal of my talk on this highly ambitious topic? To discuss the work we are doing at Obeo to facilitate the eco-design of complex systems… Not easy! Especially in front of an audience consisting of both novices and very experienced experts on this subject.

I began by explaining what is meant by a complex systems and their relationship with Obeo.

Specifically, these are systems such as trains, satellites, cars. But it can also be the IT system of a large company, or even an industrial production line.

What characterizes a complex system is that it consists of hundreds, or even thousands of components. In a hybrid car, for example, there are between 20,000 and 30,000 different parts. Whether structural, mechanical, hydraulic, electronic, interior fittings, etc. And in an aircraft like the Airbus A380, there are about 4 million parts. All these parts are designed by different teams and a myriad of subcontractors. The complexity arises not just from the number of components, but from the fact that they interact with each other, to exchange information, and collectively perform the expected functions of the system.

In the case of an autonomous car, for example, the car's behavior is not programmed directly; it emerges from the combination of interactions between the different subsystems in charge of perception , trajectory planning, and motion control.

Our mission at Obeo is to provide software that allows architects of a complex system to work together to graphically describe this architecture at the right level of complexity. So they can identify and represent the various functions of the system, how they sequence, which system components perform them. And they can share this knowledge with all concerned parties.

An example of a complex system modeling tool is Capella, the MBSE (Model-Based Systems Engineering) software developed by Thales with the help of Obeo.

In the aviation sector, for instance, Capella is used by many industries designing aircrafts. At their scale, they don't deal with the hundreds of thousands of parts that make up an airplane; they stick to the level of detail that concerns them. If we take the aircraft engine, they consider it just as a component, without dealing with the thousands of parts that make it up. However, Rolls Royce, which designs the UltraFan, a next-generation aircraft engine that saves 25% fuel, works at the engine scale. Conversely, Thales designs air traffic control systems. They recently designed the OneSky system for Australia, which is one of the most modern in the world. In this type of system, this time the aircraft is viewed as a component.

The goal with Capella is for an industry to answer three main questions:

  • Does the system I am designing meet the expected needs, and which component meets which requirement?
  • If I delegate the design of a component to another team, a partner, or a subcontractor, have we clearly understood what this component should achieve and how we will ultimately integrate it into the system?
  • If I modify this component, what are the potential impacts on other components and the overall system operation?

However, today there is a question that is very difficult to answer: what are the environmental impacts of my system?

When we talk about environmental impact, we generally think of carbon emissions. But that's very reductive because to assess the real impact, other factors need to be considered: pollution (nitrates, fine particles, radiation, heavy metals), resource consumption (energy, water, rare earths, etc.), ocean acidification, etc. And these need to be evaluated over the entire lifecycle of the system: raw material extraction, manufacturing, use, and end-of-life, with possible recycling to feed the manufacture of other products.

Credit image: ISD Engineering

To perform this type of assessment, a Life Cycle Assessment (LCA) is necessary. But the more complex the system to be analyzed, the harder it is today to produce reliable LCAs. They are generally very simplified, and since few can be performed (due to their cost), they often occur at the end of the design process, once all choices have been made.

However, if we really want to reduce the impact of the systems we produce, we must reduce the time spent conducting their LCA. This way, we can perform them more often and much earlier, right from the design phase, to evaluate different design alternatives based on their environmental impacts.

The problem today is that to perform an LCA, one must manually enter the architecture of the system to be analyzed into specialized software. This is very complicated because this information is often buried and fragmented in numerous highly technical documents. Practically, as we see with our clients, systems engineers and LCA experts rarely work together. In fact, LCA experts are mainly mobilized to draft corporate carbon footprints. They are more often asked to measure the existing rather than to seek solutions.

At Obeo, we aim to break down the barriers between the design world and LCA experts: for systems engineers to consider environmental constraints from the beginning and for LCA experts to be truly integrated into engineering teams.

The solution we are working on involves using the data already entered by systems engineers with our modeling software. The idea is to reuse this data and complete it to automatically produce LCAs.

For example, for a car, the systems engineers working on its architecture with Capella software already have a digital model describing all the main components.

 

What we propose is an extension to Capella (add-on) that allows enriching the system model by adding all the additional information needed to calculate an LCA.

This starts with the lifespans of each component, which allows calculating how many times they will need to be replaced. For example, if the car is designed to last 250,000 km and its tires have a lifespan of 50,000 km, we can automatically deduce that on average, 5 sets of tires will be needed over the car's lifespan, so the impact of the tires should be multiplied by 5.

Next, we define the expected usage profile of the system. For example, if we design a city car, we can define two driving modes: urban mode for 70% of its usage, and extra-urban mode for the remaining 30%.

Finally, we associate and quantify material or resource flows for each component. For this, we can rely on databases that already list the impacts of millions of materials, components, or industrial processes. There are several hundred thousand depending on the fields. For example, the type of fuel and the amount consumed per kilometer, in urban and extra-urban modes. The amount of steel to produce the body, the amount of energy, the amount of water, but also the waste generated.

 

All this information can be injected into an LCA software on the market (OpenLCA for example) to automatically calculate the environmental impacts, rather than entering them manually into the LCA software. This saves considerable time while avoiding input errors.

 

To evaluate the solution, we conducted several experiments on real systems: a pollution control ship capable of collecting plastic waste at river mouths and a wind support vessel.

In both cases, we managed to calculate exactly the same impacts by generating the LCA from the system model, compared to manual entry directly into the OpenLCA software. We measured a time saving of at least 50% to perform the LCA with our solution.

But besides the time saving on one LCA, our solution allows for many other analyses more easily, depending on needs:

  • Compare two architectures: with or without an electric motor.
  • Evaluate usage scenarios: urban or extra-urban driving.
  • Evaluate a single component: the engine.
  • Or all components affected by a usage scenario: engine start.

Thanks to this ability to integrate environmental impact issues at the heart of the design process, LCA becomes a real design aid tool.

 

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