G063 - Testing

Learning Objectives: By the end of this topic you should be able to: explain the importance of testing and test plans describe the purpose of test data

Testing IT systems can be complex and error prone it’s important to identify errors in the system before it is put into use, errors are likely to cost time and/or money in safety-critical systems errors could be life-threatening.

Testing: Exam questions Try to formulate answers to the following questions Use the mark schemes on the VLE to check:

Why is Testing important? to make sure the system produces expected results to identify errors any faults can be rectified to make sure the customer is satisfied system does what the customer wanted to get paid! to give confidence to the users of the system by proving that it can cope with all eventualities

The process of testing involves: plan the tests select data that will be used to test the system run the tests identify faults correct the faults user testing

Test Plans A test plan is: a list of tests to be performed, an indication of type of test, normal, erroneous, extreme valid, invalid, extreme a statement of the data to be used for the test, a list of expected results,

Test Plans

Why is a Test Plan required? so you know what to test so you know what has been tested to ensure that everything has been tested to make sure the tests can be reproduced to know if the actual results meet expected results

3 types of Test Data used: Normal or expected data to check that the system works as expected Erroneous data invalid data that might be entered by mistake Extreme data data at the lower and upper extremes of the range

Why is a Test Plan required? to test the system’s performance against the design spec. to describe each item that needs to be tested so you know what to test so you know what has been tested to ensure that everything has been tested to specify how each test will be carried out by identifying input values and showing expected output to know if the actual results meet expected results allows discrepancies to be identified to make sure the tests can be reproduced