Test Plan Question:

★ Specifying mixes of system hardware, software, memory, network protocol, bandwidth, etc.
★ Network access variables: For example, 56K modem, 128K Cable modem, T1, etc.
★ Demographic variables: For example San Francisco, Los Angeles, Chicago, New York, Paris, London, etc.
★ ISP infrastructure variables: For example, first tier, second tier, etc.
★ Client baseline configurations
★ Computer variables
★ Browser variables
★ Server baseline configurations
★ Computer variables
★ System architecture variables and diagrams

Other questions to consider asking:
★ What is the definition of "system"?
★ How many other users are using the same resources on the system under test (SUT)?
★ Are you testing the SUT in its complete, real-world environment (with load balances, replicated database, etc.)?
★ Is the SUT inside or outside the firewall?
★ Is the load coming from the inside or outside of the firewall?