The astronomical instrument GROND (Gamma-Ray Burst Optical and Near-Infrared Detector), mounted on the 2.2m MPI/ESO telescope in La Silla (Chile) is an imaging system covering seven wavelength bands from the visual to the NIR spectral range (380-2400 nm). The instrument consists of more than 30 optical elements allowing the simultaneous observation of four wavelength bands in the visible spectral range (g, r, I, z) and three bands (J, K, H) in the near infrared. The deposition of high quality optical coatings on the optical elements of the system is one of the major challenges for the implementation of GROND. In order to tailor the instrument performance with respect to the required sensitivity parameters, a set of broad band anti reflection coatings and dichroic filter coatings on quartz, YAG and different fluoride compound lenses had to be optimized. The performance and deposition control of the optical coatings on plane and curved surfaces was evaluated with the aid of witness samples, which were deposited together with the real substrate. The global optical performance of the instrument can be determined combining the single components properties or by an overall measurement of the finalised instrument. In this contribution, a comparison of the measured performance and the operation characteristics predicted from the properties of the single elements is presented.