The Biggest Problem in Performance Testing

In this article, Carlos Quiroz Vega, QA Engineer at OmniLatam, outlines the best way to do a Performance Test project.

When you begin a Performance Test project, it is typical you will find one or more details about virtual user concurrence. The process takes a time to analyze, and if it is an old app, you will need statistics or more items to help find the concurrence. On the other hand, if the app is new and you don’t have the statistics, you will need to calculate how many users you require in a Performance Test.

I will present one basic formula to calculate the concurrence and ramp-up used in a scenario.


  1. Calculate Concurrence:

U: number of users

t: time in minutes or seconds


  1. Calculate Ramp Up:

U: number of users

C: concurrence

Now, you know and can do use this formula in your Performance Testing.


How do we use these formulas in JMeter?

Choose Concurrency Thread Group:

In this case, we have one scenario: the concurrence total with a 500 vuc requires one ramp up in 30 minutes and after loading maintenance, the user continues to hold for 30 minutes. This is a total time of 60 minutes of testing. The ramp-up requires one politics load by steps.


Implement the formula of Concurrence:

Implement the formula of Ramp Up:

Replace valor in JMeter:


In conclusion, in the image, every step contains 17 users and increases ramps up every 1 minute with 17 users, during 30 minutes and holds the load for 30 minutes more. Now, you can use the formulas for your projects and calculate exactly the concurrence y capability in your app.