Once you have identified the current load levels, the next step is to understand as accurately and as objectively as possible the nature of the load that must be generated during the testing.

Using the current usage figures, estimate how many people will visit the site per week/month or day. Then divide that number to attain realistic peak-hour scenarios.

It is important to understand the volume patterns, and to determine what load levels your web site might be subjected to (and must therefore be tested for).

There are four key variables that must be understood in order to estimate target load levels:

how the overall amount of traffic to your Web site is expected to grow

the peak load level which might occur within the overall traffic

how quickly the number of users might ramp up to that peak load level

how long that peak load level is expected to last

Once you have an estimate of overall traffic growth, you’ll need to estimate the peak level you might expect within that overall volume.