Implementing sustainability approaches in wire harness production.


Bernhard Reichelmann

Kromberg & Schubert GmbH

Mr. Reichelmann is General Manager for the Quality division.


Observing sustainability over the product life cycle of the wire harness

SP 13 defines the sustainability criteria that should be taken into account in the automated production of line sets. It is important to focus on automated production and thus to distinguish it within the extensive sustainability topics.

Starting point and motivation

The current production of a wire harness is still dominated by manual activities. The frequent handling of the cable set, which can weigh up to 50 kg, is a strenuous activity for the employees and involves the risk of damage. The energy input for the production of the wire harness is low compared to the usual highly automated production of other components for the automotive industry.

Current working focuses

At the beginning of SP13, the first process set out the topic of sustainability in the context of production of an automated wire harness. The team members focused on the key evaluation criteria that must be observed from a sustainability perspective during the automated production of a wire harness. The product, the processes and the transports were identified as central work focuses for SP13.


Data collection is an essential issue for sustainability in a process. Here, a standard catalogue for components, e.g. copper, could be useful. This could be worked out independently of the fabricator. The origin of the material would have to be taken into account (where does the material come from? Where was it mined and how was it transported?). Reusability of materials is a requirement for various car manufacturers. For example, there are already demands for the use of a certain proportion of recyclate in plastics. Here, it is necessary to examine the extent to which more flexible material usability is possible.

Traceability of data is very important. How and when was the original material produced? In the case of recyclates, the question arises in which cycle one is in and how much new material has been added? How much energy is used in recycling?

The complexities of the wire harness continue to play a major role. For example, are grommets etc. still being used or can they be omitted in the automation. What is important here is the ongoing development of functional integration. Another important aspect is service life. Extending the service life of the wire harness (> 8,000 h) can lead to a reduction in the CO2 footprint. In the future, the architecture of the wire harness needs to be evaluated to see whether the new concepts can lead to a reduction in the amount of materials used. When integrating new materials, corresponding data must be supplied in order to be able to include this in the accounting.


Automated production increases process reliability and thus product safety – even after years of use.

Due to the reduction of rejects in automated production, a lower reject rate can be expected, which ultimately results in the reduction of waste.

The comparison of manual and automated workplaces is very complex and difficult to evaluate. Material and energy use for machinery should also be considered thoroughly, as this is very likely to be a relevant consideration.


Disposable vs. reusable: Reusable is not necessarily more clever, as wooden or cardboard boxes, for example, offer easier disposal at the destination following intercontinental transports. Furthermore, the transport quantity of dimensionally stable wire harnesses must also be evaluated. It is necessary to check whether larger packaging is necessary. The entire supply chain, from subcontractor to OEM, must be taken into account. The transport of employees to the production sites must not be neglected here, as the sites are often located in low-cost countries and employees are transported to the production sites by bus. Automated manufacturing can achieve a reduction in manual activities and a move away from production in low-cost countries.


The topic of sustainability is a cross-sectional function across all other sub-projects. When considering the influencing factors and boundary conditions, intensive exchange of data with the other sub-projects is necessary.

A digital twin would be one way of exchanging information that would enable the project to achieve more sustainable production by collecting data across the entire value creation process. The involvement of suppliers in the methodology of data collection as well as the comparability of data will play a central role, as much data is not collected or simply not known during the development process.

At this point, the following key questions need to be answered:

  • How is data verified, what data quality is required and how is it stored?