Model-Based Simulation of Manufacturing Systems

Problems associated with complex manufacturing systems

Today, constantly changing customer requirements are forcing companies to control increasingly complex production processes. This is reflected in the mounting number of product functions and variants required by end-users as well as in rising demands concerning quality, flexibility, service time and the desired level of service. The main requirement is for shorter product planning and development times. The slightest modification demanded by the customer causes turbulences in the production process. This has a major negative impact on a manufacturing system’s robustness and stability.

To optimize these systems, simulation studies are often conducted. However, with virtual models it is not an easy task to define benefits or costs. Costs generally depend on the model’s degree of detail and benefits on the anticipated results.

Project procedure

As a rule, Fraunhofer IPA starts by determining the degree of detail required for the virtual model in order to obtain the best results with the budget stipulated by the customer.

The project has five phases:

1. Analysis, formulation of the problem and collection of data
2. Abstraction of the system to be simulated and generation of the model
3. Implementation of the generated model in a virtual model
4. Simulation experiments concerning target parameters
5. Analysis and documentation

The project is conducted in joint workshops with the customer. The actual virtual model is generated at Fraunhofer IPA using a software tool (Tecnomatix Plant simulation 11 from Siemens Industry Software).

Aims and benefits

A simulation can be used to improve processes as well as to identify problems at an early stage. Examples include:

• Avoidance or elimination of bottlenecks,
• Process optimization of any target function (e.g. throughput times, capacity, yield),
• Optimization of work processes and contents,
• Optimization of buffer sizes and warehouse stocks,
• Reduction in or simplification of system elements or controls elements, and also
• Simulation of the planned system on the basis of possible courses of action.