Frequently Asked Questions Types of Testing: Testing presents an interesting anomaly for the software engineer. Earlier in the software process, the engineer attempts to build software from an abstract concept to a tangible implementation. Now comes testing. The engineer creates a series oftest cases that are intended to “demolish” the software that has been built. In fact, testing is the one step in the software engineering process that could be viewed as destructive rather than constructive. Software developers are by their nature constructive people. Testing requires that the dev eloper dis car d precon cei ved not ion s of the cor rec tne ss of sof tware jus t developed and over come a conflict of interest that occurs when er rors are uncovered. Testing Principals Davis suggests a set of testing principals, which have been adapted for use: 1. All tests should be traceable to customer requirements. 2. Tests should be planned long before testing begins. 3. The Pareto principal applies to software testing. 4. Testing should begin “in the small” and progress toward testing “in the large”. 5. Exhaustive testing is not possible. 6. To be most effective, testing should be conducted by an independent third party. Pareto Princi pal: Simply put, the Paret o principal implies that 80% of all error s uncovered during testing will likely be traceable to 20% of all program modules. Testability The che ckl ist tha t fol lows pro vid es a set of cha rac ter istics tha t lea d to testab le software. 1. Operability – The better it works, the more efficiently it can be tested. 2. Observability – What you see is what you test.
