en Mathematical Modeling and Applications of OR Mathematical Modeling and Applications of OR پژوهشی Original <em>This pa</em><em>per analyzes the performance of a robotic system with two machines in which machines are configured in a circular layout and produce non-identical parts repetitively. The non-destructive testing (NDT) is performed by a stationary robotic arm located in the center of the circle, or a cluster tool. The robotic arm integrates multiple tasks, mainly the NDT of the part and its transition between a pair of machines. The robotic arm cannot complete the transition if it identifies a fault in the part. The main feature of the NDT technology is that its required time is changed by altering the testing cost. This generates a trade-off between cost and cycle time. Initially, the problem of robotic arm scheduling and part sequencing is jointly solved to supports the decision making for reliability improvement of small-scale robotic systems with NDT technologies. We show how the case of non-identical parts can be converted into a travelling salesman problem (TSP). Then, we provide a generalization of the framework based on three characteristics: pickup criterion, layout and travel time metric. The results are extended for the interval and no-wait pickup criteria, and then some notes are provided for travel time saving of different layout and travel time metric. It is shown whether circular</em> <em>systems are equivalent to linear</em> <em>systems, or they dominate linear</em> <em>cases in general terms.</em> Performance analysis, Robotic systems, Non-destructive testing, Scalarization 1 17 http://iors.ir/journal/browse.php?a_code=A-10-1422-7&slc_lang=en&sid=1 Mehdi Foumani مهدی فومنی mehdi.foumani@unimelb.edu.au 1111111111 1111111111 Yes The University of Melbourne The University of Melbourne Reza Tavakkoli Moghaddam رضا توکلی مقدم tavakoli@ut.ac.ir 1111111111 1111111111 No University of Tehran دانشگاه تهران