Ready-To-Assemble (RTA) furniture is becoming increasingly popular due to attractive pricing compared to standard furniture. However, for this kind of furniture to be attractive to the customer, the assembly process must be smooth. If the assembly requirements are fulfilled or not is, for this kind of assembly, ruled by the tolerances on part level. In this paper, a methodology for variation simulation of RTA furniture is presented. By predicting the fulfillment of requirement on assembly level, reasonable tolerances on part level can iteratively be set, to guarantee a smooth assembly process. The methodology includes material models, flexibility and bending during assembly, contact modeling and modeling of fastener elements between parts. Variation simulation is commonly used in the automotive industry and a comparison of variation simulation methodologies between the two kinds of industries is conducted. A major difference between RTA furniture business and automotive industry is that no fixtures are used for RTA furniture. This must be reflected in the simulation procedure. Furthermore, the results from the variation simulation need to be evaluated, and the results are dependent on the context of the assembled product. Both the assemblability and esthetical requirements, like flush, gap, and parallelism, need to be evaluated.
The methodology is illustrated on a case study and future development and research needed to adapt variation simulation to furniture industry are discussed.