Based on the definition of the European Commission, small enterprises can be defined as companies with less than 50 employees. Medium size companies are companies with less than 250 employees. For small and medium enterprises some research in regards to ERP selection criteria has been done. But this research did not distinguish further in the different behaviors that can be found during the ERP selection process within different types of companies. Different characteristics which appear from an IT operational point of view on how small and medium size businesses organize their IT have not been taken into consideration. This paper gives the definition of a specific group of companies named orchestra companies within the SME band. This is done by limiting the quite broad definition of the European commission and applying an IT operational viewpoint. Further the different requirements of orchestra companies in regards to the ERP selection process are formulated. To correlate the ERP selection criteria and the different behaviors from an IT operational point of view, a segmentation of orchestra companies is developed. For each segment the focus on specific ERP selection criteria is discussed. Furthermore is an application of the segmentation on technical ERP selection criteria applied.