Determine Input Parameters for Instance-Specific Reliability Models in the Circular Factory

The vision of the Circular Factory (CF) is to extend product lifecycles by transforming used products into new generations through sustainable practices such as reuse, reconditioning, and remanufacturing. It aims to create perpetual innovative products. Achieving this vision requires developing instance-specific reliability models capable of predicting functional behavior at both subsystem and system levels supporting decision making for control of the CF. One challenge in building this reliability model is to identify input parameters that not only allow accurate predictions of functional behavior, but also account for time-dependent changes and interactions at both the subsystem and system levels within the CF. This study introduces a framework to determine the input parameters for instance-specific reliability models in the CF.
An angle grinder is used as an exemplary application of the proposed framework. The framework consists of five steps: (1) system decomposition, where the angle grinder is broken down into subsystems and components; (2) component prioritization, which identifies the elements most relevant to the functional behavior; (3) use case analysis, which examines how different operational scenarios affect component performance and failure modes; (4) failure mode identification, which links failure modes to the components; and (5) input parameter extraction, where the necessary input variables for the reliability model are extracted based on the results.
This study focuses on tooth breakage as it serves to illustrate the application of the framework through a single example. Identifying the correct input parameters lays the foundation for developing instance-specific reliability models that integrate various failure modes and subsystems within the CF. However, the framework is limited by its focus on a single failure mode, which restricts its generalizability. Future work should address multiple failure modes and validate the framework across diverse use cases.

Keywords: Reliability model, Circular factory, Remanufacturing, Functional model, Angle grinder.