I usually measure and record all these as they will, over time, all vary with system problems, start-up processes, changes to applications, changes to the machine specs, change of models of PC purchased and so on. Have a record of just what these times were at original build can be quite helpful.
On when the final test should finish (3 apps open) there can be value in not just having the app open but having performed a simple first use (e.g. a browser will load a home page and this may suffice; a word processor could load a test document (same for every test: already loaded at least once previously if on a network resource)).
In a few cases a more detailed analysis is worthwhile. Being network-centric I would usually look at timings from power-on such as:
- First network transmission (typically a BOOTP/DHCP request)
- Time for network load/DHCP set-up and server(s) being used
- Time for DNS responses and server being used
- Time to end of start-up network activities (e.g. licence/update checks)
- Time for browser home page start/end
- Time to quiescent (if ever)
Typically these would be done by noting the time on power-up and then looking through a tcpdump or wireshark trace subsequently.
Again, a record of this, perhaps with indications of numbers of frames and total bytes, is helpful as software and systems changes and as a reference in the event of problems.