Where does Exploratory Testing fit?

In general, ET is called for in any situation where it’s not obvious what the next test should be, or when you want to go beyond the obvious tests. More specifically, freestyle Exploratory Testing fits in any of the following situations:

• You need to provide rapid feedback on a new product or feature.
• You need to learn the product quickly.
• You have already tested using scripts, and seek to diversify the testing.
• You want to find the single most important bug in the shortest time.
• You want to check the work of another tester by doing a brief independent Investigation.
• You want to investigate and isolate a particular defect.
• You want to investigate the status of a particular risk, in order to evaluate the need for scripted tests in that area.

Pros and Cons:

Pros

• Does not require extensive documentation.
• Responsive to changing scenarios.
• Under tight schedules, testing can be more focused depending on the bug rate or risks.
• Improved coverage.

Cons

• Dependent on the tester’s skills.
• Test tracking not concrete.
• More prone to human error.
• No contingency plan if the tester is unavailable.

Exploratory testing fits almost in any kind of testing projects, projects with rigorous test plans and procedures or in projects where testing is not dictated completely in advance. The situations where exploratory testing could fit in are:

• Need to provide a rapid feedback on a new feature implementation / product
• Little product knowledge and need to learn it quickly
• Product analysis and test planning
• Done with scripted testing and need to diversify more
• Improve the quality of existing test scripts
• Write new scripts

The basic rule is this: exploratory testing is called for any time the next test you should perform is not obvious, or when you want to go beyond the obvious.
A Good Exploratory Tester
Exploratory testing approach relies a lot on the tester himself. The tester actively controls the design of tests as they are performed and uses the information gained to design new and better ideas.
A good exploratory tester should

• Have the ability to design good tests, execute them and find important problems
• Should document his ideas and use them in later cycles.
• Must be able to explain his work
• Be a careful observer: Exploratory testers are more careful observers than novices and experienced scripted testers. Scripted testers need only observe what the script tells. Exploratory tester must watch for anything unusual or mysterious.
• Be a critical thinker: They are able to review and explain their logic, looking out for errors in their own thinking.
• Have diverse ideas so as to make new test cases and improve existing ones.

A good exploratory tester always asks himself, what’s the best test I can perform now? They remain alert for new opportunities.
Advantages
Exploratory testing is advantageous when

• Rapid testing is essential
• Test case development time not available
• Need to cover high risk areas with more inputs
• Need to test software with little knowledge about the specifications
• Develop new test cases or improve the existing
• Drive out monotony of normal step – by - step test execution

Drawbacks

• Skilled tester required
• Difficult to quantize

Balancing Exploratory Testing with Scripted Testing
Exploratory testing relies on the tester and the approach he proceeds with. Pure scripted testing doesn’t undergo much change with time and hence the power fades away. In test scenarios where in repeatability of tests are required, automated scripts having an edge over exploratory approach. Hence it is important to achieve a balance between the two approaches and combine the two to get the best of both.