WordPress is not only CMS its a platform for building "Web of Things". WordPress can be scaled, like any system. If you make something with care and proper utilisation of tools, WordPress can do anything. Only your imagination is the limit. WPERP system consists an HR and CRM in its core plus a full-fledged Project Management and Accounting system as a separate add-ons. The best part is, all of these are FREE and open-source.