The NAV 2017 distribution includes a charting capability that is based on a Control Add-In which was created with .NET code written outside of C/SIDE and integrated into NAV. An example is the Trailing Sales Orders chart in a Factbox Page part (Page 760) that appears in the Order Processor Role Center (Page 9006), as shown in the following screenshot:

The article, Cash Flow Chart Example, (https://msdn.microsoft.com/en-us/library/hh169415(v=nav.90).aspx) in the NAV 2017 Developer and IT Pro Help describes how to create charts using the Chart Control Add-In.