The printed circuit board (PCB) assembling production process is generally optimized to ensure very low levels of errors (defects) so as to produce the higher quality product. The evaluation of efficiency of different types of PCB (cards) could help the management in identifying the quality of assembly process to work out appropriate interventions to prevent failures. This study uses the technique of data envelopment analysis to assess the efficiency of cards across all assembly units as well as within its respective assembly unit in the presence of undesirable outputs under the assumption of weak disposability. In our case, the three types of errors, viz.; machine error, manual errors and other errors that occur in the defective assembled PCBs are considered as the undesirable outputs. In-depth analysis has been carried out through jackknifing analysis to check the robustness of DEA efficiency scores. The best practice group of cards for each inefficient card has been identified which eventually facilitate the management to derive the level of undesirable outputs to be reduced and desirable output to be improved so as to achieve the level of efficiency at par with its practice group. © 2011 Elsevier B.V.