Abstract
	The capability of a process is a measure of its ability to satisfy customer’s requirements. Process capability studies are carried out to compare customer’s requirements with process performance to identify the resources for process measuring (monitoring). The measurement process is realized in measurement system, which involves measurement equipment, methods, appraisers, software, conditions of environment and other factors. If the analyzed measurement system is capable, it is likely that the measurement process, taking place in it is capable as well. One of measurement systems analysis (MSA) methods, analysis of repeatibility and reproducibility (GRR) was used for evaluation of measurement’s capability of green sand mold compression strength RC2, shearing strength RT2 and mold permeability. Molding processes were sand is used to make the mold produce by far the largest quantity of castings. Good castings cannot be made without good – class molds. Because of the importance of the mold, the quality of casting processes are often described by the materials and methods employed in molding. Ten samples of green sand with various content of dust were measured by routine methods by two appraisers in two trials. Analyzed process is capable for measurement measurement of permeability, but non-capable for measurement of strenght. The increasing of capability could be possible by increasing of discrimination (more fine scale).  The influence of appraisers on capability is positive with negligible difference in their competence.