Lidl has the ambition to separate waste streams more effectively and consistently, but in day-to-day practice employees regularly ran into confusion and complexity. How do you design a work environment where good waste separation happens almost automatically, even during peak hours? In the project *Behavioral Intervention Waste Separation Lidl*, we worked together with Lidl to investigate how employees across various stores experience the waste separation process, and how the design of a waste separation unit in the warehouse can better support them in sorting waste correctly.
Lidl came to us with a clear question: how do we make the waste separation process simpler, more intuitive, and more reliable for all employees, so that waste ends up in the right category? The challenge was to develop a design for the waste separation unit that supports employee behavior, regardless of language level, experience, or workload.
We conducted observations in stores and spoke with employees and team leaders about current behavior and the associated challenges. From this we learned the following: employees genuinely want to do the right thing, but the process still takes too much time and mental effort, leading to quick mistakes; visual communication at the unit is the most important reference point for almost everyone; and spatial design choices — such as clarity and visibility around the unit — have a major influence on behavior. The biggest improvement came when employees had to think less and the environment almost automatically facilitated the right behavior. This led to one dominant direction: How do we design a flow that automatically guides employees to the correct waste category?
The final solution is an intuitively designed decision-making process, linked to the different waste streams. In the pilot, the flowchart led to a significant reduction in errors: from largely incorrectly sorted streams in the baseline measurement to largely correctly separated streams in the follow-up measurement.
We developed a new, language-free flowchart that makes the waste separation process clear with as little mental effort as possible. This flowchart was tested in two stores, including a baseline measurement beforehand.
The approach consisted of:
- Observations and behavioral analysis in stores
- Development of intuitive categorization
- Testing for ease of use and error reduction
- Short interviews with employees and team leaders
- Analysis of before and after measurements to determine impact
The design combines behavioral science and visual design into one logical system.
We designed:
- A language-free flow that guides employees through the decision-making process
- An icon set that works intuitively, even for employees with limited language skills
- A visual framework for future communication and potential upscaling
During testing, the design immediately led to fewer errors, less hesitation, and greater consistency. This resulted in cleaner waste streams and less residual waste.
When rolled out on a larger scale, this design means less contamination within waste streams and a higher yield from reusable streams.
