Automated Container Washing Line Optimization with Simulation | Case Study

The client faced the task of designing a complex technological line consisting of:

• multiple washing and drying sections,
• robotic loading and unloading systems,
• conveyors,
• buffers,
• turntables,
• and a scalable structure (base variant: 4 washing sections; future variant: 6 sections).

While the initial concept defined cycle times and target throughput, the client needed to verify real feasibility before starting mechanical design. Due to the system’s complexity, key risks included:

• bottlenecks and congestion,
• lack of synchronization between sections,
• failure to meet performance targets,
• costly modifications during commissioning (estimated risk: over €100,000).

Key questions:

• Will the line achieve the required throughput?
• Will the expected technical availability be met?
• What changes are needed to ensure process stability?
• How will the system behave after expansion?

Simulation objectives:

• Validate cycle time depending on the number of sections
• Analyze alternative line configurations
• Provide 3D visualization

Solution: Advanced Process Simulation in FlexSim

Nextomation used production line simulation and digital modelling in FlexSim to recreate the washing system and evaluate its behaviour before physical implementation. The simulation reflected the planned process flow, machine logic and interactions between individual stations, providing a reliable basis for further engineering decisions.

This approach is also widely used in the development of custom automated assembly lines, where validating throughput, layout assumptions and equipment cooperation at an early stage helps reduce implementation risk and improve system performance.

To better understand why simulation matters in automation design, the project focused not only on visualising the concept, but also on verifying critical operational parameters such as station utilisation, material flow, buffer levels and robot workload.

Similar benefits can be seen in our tea-bag packaging simulation case study, where simulation also supported decision-making by helping assess alternative line concepts and optimise the final solution.

The simulation model included:

• 2D layout and topology,
• all washing modules, turntables, and robots,
• cycle times (variant 1: 90 s; variant 2: 60 s),
• buffer logic,
• roller transport,
• robot utilization,
• real-time material flow.

The same simulation-driven approach can also be applied when developing custom automated assembly lines, where throughput, equipment interaction and scalability need to be verified before physical implementation.

Watch the simulation we have designed:

Key steps:

1. Mapping the initial concept
A complete model based on the client’s assumptions enabled early identification of issues not visible in static 2D layouts.

2. Bottleneck analysis
The simulation revealed:

• linear tray buffers as a key bottleneck,
• upstream filling logic causing congestion at the end of the line,
• full throughput reached only after several hours,
• robots periodically idle, reducing technical availability.

3. Buffer redesign

• A new buffering strategy was developed:filling buffers from the end,
• adjusting tower capacities (10/14/18 positions depending on variant),
• modifying transport speed (0.3 m/s),
• dynamic batch filling,
• full synchronization with robot cycles.
• This significantly improved process stability.

4. WHAT-IF analysis
Tested scenarios included:

• 4-section base variant,
• 6-section future expansion,
• different buffering logics,
• varying numbers of robots.

All without building a physical prototype.

5. Comprehensive deliverables
The client received:

• 3D animations of the process,
• simulation videos of buffer behavior,
• detailed datasets (~50,000 events),
• performance and robot utilization charts,
• updated layout with recommended changes.

• Full line performance achieved in 33 minutes (instead of several hours)
• Stable buffer operation without robot waiting time
• Elimination of congestion at the end of the line
• Confirmed cycle time feasibility (90 s → 40 units/hour; 60 s → 60 units/hour)
• Enabled safe expansion to 6 sections
• Balanced robot utilization (e.g. 83% for one robot in a scenario)
• Reduced risk of design errors

Business benefits:

• Strong support in tender processes (data, charts, visualizations)
• Avoided commissioning modification costs (> €100,000)
• Faster concept validation without physical prototypes
• Increased project predictability for the end customer
• Proven scalability of the solution

Simulation allowed the client to:

• verify feasibility before physical implementation,
• analyze buffer behavior in detail,
• eliminate conceptual errors,
• evaluate alternative scenarios,
• shorten design and implementation time,
• minimize technological risk,
• define robot workloads and parallel operation potential,
• prepare clear visual materials understandable also for non-technical stakeholders.

Thanks to advanced simulation by Nextomation, the client not only confirmed that the line would work but also received a set of actionable recommendations that improved stability, ensured scalability, and enabled confident discussions with the end customer.

Simulation became:

• an engineering tool,
• a sales support asset,
• a foundation for business decisions,
• and a key factor in reducing costs and risks.

This project is a strong example of the value delivered by combining analytical, technological, and consulting expertise in complex production systems. This type of simulation-led analysis can also form part of a broader production scaling and efficiency programme, covering capacity, process, automation and investment decisions before implementation.