As you go through your normal yearly planning cycles remember that in January 2020 Microsoft will be retiring Windows Server 2008 R2, Windows 7, and Microsoft Exchange 2010. That means no security updates and no vendor support if something goes wrong.
That means that summer 2019 is the last major chunk of time you have to perform the necessary migrations.
All of those migrations require planning and may involve costs depending upon whether you have a campus agreement with Microsoft or not as well as the labor and possible hardware required. Also, you may need an updated deployment strategy to roll out Windows 10 machines.
Microsoft recently stated that Windows 10 represents approximately 50% of the workstations out there. That is a good start.
Depending upon what you are running on those Windows servers there may be other vendors involved, separate SQL server upgrades, VMware upgrades, etc.
If you intend to ask for our assistance in planning or implementing the migrations, very quickly we should begin talking about these projects so you have what you need and we have you on our radar as the summer schedule is developed.
If I am talking about your network environment, let's start talking about what needs to get done and define the projects and costs.