Not only the values of the product properties of cement but also their uniformity are crucial quality criteria. Fluctuations of customer relevant properties, such as early strength and workability and their determining physical, chemical and mineralogical parameters have been characterized in the frame of this work. The investigated properties do not only fluctuate stochasticly, but with trends, shifts and temporarily peaks. For their quantification a statistical procedure was developed that quantifies the short-term and long-term fluctuation. With it the data of 25 cement works and 5 grinding stations without own clinker production were evaluated and benchmarked. Case studies complement the statistical evaluation and show works and cement specific fluctuations and their causes. These causes were classified and evaluated concerning their impacts on product uniformity. Hence, feasibilities for the optimisation of uniformity were deducted.