%% Last Updated: - [[2021-02-10]] Related - [[Load Testing]] [[Performance Testing]] %% A workload model is a schema describing the load profile for a given test scenario, and it involves determining _what_ (the key transactions), _how much_ (the load distribution among the transactions) and _when_ (timing of the load) to test. ^e8be7e Workload modeling can be the most difficult part of the testing process because it involves finding out how load test scripting can best mimic what is actually happening in production. It can also be the most critical. Imagine a project that runs load tests of the guest checkout process on their e-commerce site. Despite having tested up to 1,000 concurrent users on their production-like environment and getting sub-two-second response times, they get response times of greater than a minute in production before their servers start to go belly up. What could have gone wrong? Well, a lot of things, but one thing they may not have taken into account is the standard user path. Perhaps they assumed that most customers would checkout as guests without logging into their accounts, but in reality, 90% of their customers log in before checking out. This means that there’s a big gap in their testing: user login. Perhaps it wasn’t the main application server that ran into issues at all; it could have been their authentication servers. Workload modeling ensures that you’re testing what you need to test, but it can be more complicated than it sounds. ## See also - [[Workload Modeling - Preparing for Large Events Like the Melbourne Cup]]