random order of execution of testcases in a loadtest

hi,

I would like to the load test to simulate interaction with a service. Each of my testcases in my testsuite has a loadtest. Each testcase represents one type of interaction such as 'get customer', 'get account', 'create subscription' etc.

I would like to run the loadtest in such a way that the execution of test cases occurs in random order.

So far I have been able to run a loadtest from load test runner but it executes test cases (their corresponding loadtest) one by one i.e. it runs TC1 first for a minute then TC2 and so on. I want to achieve more natural traffic where operations occur concurrently i.e.  

Is there a way to achieve it (without starting 15 SoapUIs and event then how to add randomness)?

A