Before client–server architectures evolved in the late 1980s, many HR automation processes were relegated to mainframe computers that could handle large amounts of data transactions. In consequence of the high capital investment necessary to buy or program proprietary software, these internally developed HRMS were limited to organizations that possessed a large amount of capital. The advent of client-server, application service provider, and software as a service (SaaS) or human resource management systems enabled higher administrative control of such systems.