Most people create several scripts to accurately reflect different types of users. Scripts execute simultaneously in order to hit your site with the correct mix of traffic. You control the weighting of each script by giving it a number relative to the others. For example, if you have 2 scripts and you give one a weighting of 4 and the other a weighting of 1, then the first will generate 80% of the traffic and the second 20%. This 80/20 could be realistic for a retail e-commerce site where most of the people (80%) are browsing the product catalog, while a minority of people (20%) are going through a buying experience. You can of course throw in a low-weight scenario to represent some internal employees adding products or issuing refunds.

Another way of entering the weight of the traffic is to just enter the exact percentage you would like each script to carry. For the example above you would simply enter 80 and 20. The only thing you have to be very careful about is that the percentages add up to 100. Otherwise, it will work like the above description, which is different.

There is no limit to the number of scripts you can create, and you can use many scripts in a test. We encourage you to build as many as necessary to accurately reflect the real traffic patterns on your site. That will give you the most meaningful metrics for tuning your applications.

We also simulate the user “think time” with random pauses after each page. Real users click on something, then read the page or fill in a form, and then click on something else. Thus, you don’t want to have a simulated virtual user clicking on something every .5 seconds – it would not give you meaningful results if you want to see how your site holds up in the real world.

Also see: Virtual User Calculations about calculating the amount of virtual users needed for a realistic test.