Investigation on surface roughness of thin films is an important issue in manufacturing engineering because the performance of a coated film is significantly affected by the surface roughness of thin films. A fast and flexible optical measurement system to measure surface roughness of hard coatings deposited by cathodic arc evaporation is developed in this work. The objective of this work is to examine the repeatability and reproducibility (R&R) of an optical measurement system. Percentage of equipment variation, appraiser variation and R&R is 7.25%, 1.42% and 7.39%. Thin film optical measurement system developed is acceptable according to the measurement systems analysis and the R&R technique. (C) 2012 Elsevier GmbH. All rights reserved.