error while running multiple tests in execution plan

Hi, I am doing the UI testing of an application in testcomplete. I have made several testcases by recording the actions that I perform and in each case I am opening and closing the application. So while running these testcases each time the testcase should be opening, performing some steps and then closing. But in my case the first test is running smoothly but the following tests fail as the first test takes some time in closing and at that time the checkpoints of the next testcases starts its verification. How can I solve this issue?