Topic: Automated Testing Methodologies

Now that we’ve eliminated Record/Playback as a reasonable long-term automated testing strategy, let’s discuss some methodologies that I (as well as others) have found to be effective for automating functional or system testing for most business applications

The "Functional Decomposition" Method

The main concept behind the "Functional Decomposition" script development methodology is to reduce all test cases to their most fundamental tasks, and write User-Defined Functions, Business Function Scripts, and "Sub-routine" or "Utility" Scripts which perform these tasks independently of one another. In general, these fundamental areas include:

1. Navigation (e.g. "Access Payment Screen from Main Menu")
2. Specific (Business) Function (e.g. "Post a Payment")
3. Data Verification (e.g. "Verify Payment Updates Current Balance")
4. Return Navigation (e.g. "Return to Main Menu")

In order to accomplish this, it is necessary to separate Data from Function. This allows an automated test script to be written for a Business Function, using data-files to provide the both the input and the expected-results verification. A hierarchical architecture is employed, using a structured or modular design.

The highest level is the Driver script, which is the engine of the test. The Driver Script contains a series of calls to one or more "Test Case" scripts. The "Test Case" scripts contain the test case logic, calling the Business Function scripts necessary to perform the application testing. Utility scripts and functions are called as needed by Drivers, Main, and Business Function scripts.