Multiple people can more easily discuss and cooperate in testing when a significant portion of the test work is written down. Members of your organization who are not programmers can run test scripts and learn how to write very good test scripts. Encourage people to keep some kind of record of what they re doing. Then bugs that are discovered can be more readily reproduced and isolated, and the techniques used to uncover those bugs can make their way into subsequent versions of test scripts. Another way to attack this problem is by automating those tests.
Test automation is a fairly sophisticated technique.
It is strongly suggested that your organization go through a few projects with increasingly rigorous manual test scripts before you embark on any kind of significant test automation plan. You need to understand many things about your engineering process before you can make a good decision about test automation. By the time it is a good business idea to do this test automation, you will recognize the need and will have had plenty of practice with engineering process improvement. Each time someone carries out a test script, or performs some free form testing, he or she should write down what script was run, what version of the product it was run against, and what the results were. All tests passed except 2c.