The process historian is usually at the center of any Industry 4.0 initiative and shouldn’t be taken for granted. An industrial process historian, sometimes called a PIMS (Process Information Management System) is a specialized database designed for the efficient collection and storage of time series data.  General purpose databases like SQL and Oracle are designed to store many data formats, often in many interconnected tables.  Process historians are designed to store relatively simple data formats, but often use compression techniques to efficiently store the data.  How a process historian collects the data is also important.  Process historians are designed to communicate using numerous standard and proprietary protocols to collect data from both common and obscure PLC and DCS platforms.  They often also offer redundant and/or buffered communication options.  It is not uncommon for process historian packages to come bundled with a more traditional database application like SQL to store other plant and equipment information outside of process data, further demonstrating that the two types of databases are not interchangeable.  Lastly, process historians nearly always come bundled with a variety of trend viewing and analysis packages.  For many clients, these trend viewing packages are the face of the product and can substantially influence buying decisions.