Planning final assembly lines can be tricky: there are often methodical or operational deficits in planning that can lead to suboptimal solutions being favored. Time-consuming and costly change loops are then the result. We shed light on how assembly lines of tomorrow should be planned.

Assembly lines and systems in the automotive industry must be designed in such a way that both the assembly systems themselves and the product to be manufactured meet their requirements - requirements on the part of employers, employees and clients alike. However, especially in the early phases of the planning process, there is often a deficit of appropriate methods and corresponding data. The result is suboptimal solutions and costly deficiencies in production, some of which remain unresolved for years.

The main reason for this is probably the position of assembly in the value chain: Assembly is located near the end of the entire value chain. Stakeholders often want to 'just kick the ball into the goal' here - but this then comes at the expense of quality and efficiency.

Outsourcing is not always an option either. Quality fluctuations, differences in required quality, additional costs or uncertainty in meeting deadlines lead to increased complexity as well as unnecessarily increased risk.

What should assembly line planning look like instead?

By using certain schemes in the planning and design of assembly lines, the greatest financial or organizational risks can either be eliminated altogether or at least greatly limited.

A correct planning scheme should be transferable to virtually all assembly systems and at the same time be able to take into account the technical, economic and organizational aspects of system design. Investments should be kept as low as possible, efficiency as high as possible - in addition, a suitable degree of automation should be applied.

Main steps of assembly line planning

  1. Analysis of the general conditions
  2. Formulation of the project goals
  3. Economic planning and determination of the appropriate degree of automation
  4. Organizational and personnel planning
  5. Realization and implementation
  6. Continuous data collection and analysis

1. Analysis of the general conditions

If you want to analyze correctly, you should ask many - and above all the right - questions. The central question of this step: What is the task at hand? The clean formulation of the answer to this question should form the foundation of all further steps. Stakeholders should also find out:

  • What is the current status?
  • What are the main milestones of the project?
  • What is the investment volume?
  • Is there a location, sufficient space and a suitable team?

2. Formulation of the project goals

The data collected in point 1 can be used to specify the project objective. The objectives should be formulated in such a way that the requirements framework for the assembly line can be derived from them at the same time.

3. Economic planning and determination of the degree of automation

In the case of fully automated or semi-automated assembly lines, which are commonplace in the automotive industry, this is the point at which the degree of automation should be determined. The possible degree of automation is mainly influenced by six factors:

  • Investment volume
  • Planned sales volume
  • Number of parts to be processed
  • Planned number of (equipment/motorization) variants
  • Personnel costs
  • Complexity of assembly steps

The rough economic planning of the assembly system, for example following the work of Konold and Reger, should accordingly already include the degree of automation.

In the rough, economic planning of the assembly system, attention should also be paid to modularity wherever possible - only modular assembly systems are truly flexible, scalable and reusable.

Standardizing assembly systems in the first place is the right way to design and implement assembly lines that are truly reliable and economical.

4. Organizational and personnel planning

The organizational and personnel planning of the assembly line includes the work organization and the design of the workplaces: Which operating resources and equipment are required? How high would the personnel requirements be and in which shift system should work be done? How economical would the whole thing be? 

Requirements with regard to the sequence of individual work steps, assembly in general, and with regard to the valid assessment of ergonomic parameters for the system operator can already be planned in this step: Virtual reality solutions not only take these aspects into account in the planning of assembly systems, but also include occupational safety, environmental protection, and fire protection in a highly descriptive manner.

5. Realization and implementation

Now it is time to turn ideas and concepts into reality. This step includes, for example, training personnel and preparing work systems and manufacturing instructions, preparing test instructions and procuring necessary work equipment.

Then it's on to trial operation - where process, performance and operational data should already be collected. Any problems must be identified, recorded and eliminated.

6. Ongoing data collection and analysis

Even after the commissioning of an assembly line, planning and conception do not stop if the assembly system is to be up-to-date, application-oriented and reliable.

Continuous data collection and analysis of the collected data not only enables the most trouble-free production possible via predictive maintenance, but also helps in the planning and design of upcoming assembly lines, which always suffer from a lack of reliable, resilient production data.


Application-optimized assembly lines in automotive production must meet the requirements of as many stakeholders as possible. The use of the right planning scheme ensures a big step in the right direction here. Apart from the correct planning methodology, the standardization, modularization and scalability of assembly lines as well as the selection of the appropriate level of automation are probably the most important guarantees for success.

If you are not sure which elements of your production can or should be automated, or if you want to strengthen the modularity of your assembly line concept, feel free to contact us. In a non-binding discussion, we can jointly determine what LEWA Attendorn can also do for your company.

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