Even in a small business having defined roles is useful, as you need to know what to put on job advertisements. Also, having a defined job title allows for promotion (which is sometimes more beneficial than a pay rise) when the situation warrants it.
In the most basic terms, the break down of testing/QA roles is:
- Junior - this person lacks experience and will run tests that have been created by someone else.
- Intermediate - this person will create test packs for defined areas, based on a test design created for them.
- Senior / Lead - This person will be responsible for the design of the test approach and the sign off of the testing effort
- Manager - Responsible for the strategic implementation of testing, resource management and the bureaucracy associated with their team
If you have a small organisation, work top down from the Senior Test position. A good senior tester will ensure that your product works correctly. Intermediate and Juniors are best used to "free up" your senior tester so you don't need those until the work load becomes too taxing.