The Systems Life Cycle: Development and testing Does the system work as expected?

So far… You have learnt about the stages involved in Analysis Design So what comes next... Creating the system Testing the system Improving the system

Testing Each time that testing shows a problem there will need to be further... Analysis Development Testing This cycle can happen many times until the system is perfect Development Testing Analysis

Creating data structures and program modules Once designed by the systems analyst these must be created by the programmer The programmer will follow the system analysts designs. E.g Using the recommended programming language Using the recommended software

Some businesses are able to use existing software to create their desired result Access and Word for example could be used to mail letters to clients Other businesses have to have a programme specially written for them this is know as: Purpose built - OR - Bespoke

Test student D.O.B in school database Testing strategies The systems analyst will have created a test plan. They will also have prepared a set of test data together with a list of expected results Test Test Data Expected results Actual results Comments Test student D.O.B in school database 16/04/1992 Accepted 09/09/2007 99/99/9999 Rejected

Test data Usually three types of data are tested Normal – data which should be acceptable or valid in the system. Extreme – only used when a range of data is used. Extremes of the range are tested. Abnormal – Data which is not acceptable or valid in the system. Lets look back at the data on the previous slide – which is which?

Test student D.O.B in school database Copy the test plan table and try to come up with some more tests that you’d recommend a school tried on their new system. Test Type of data Test Data Expected results Actual results Comments Test student D.O.B in school database Normal 16/04/1992 Accepted Extreme 09/09/2007 Abnormal 99/99/9999 Rejected

Live data Data which is already used by the business can be used to test the system. The data output from the new and old systems should match. If there are differences then there is a problem to be found and solved.

Improvements After the test plan has been fully tested the systems analyst will have to check the results Are there any problems which need to be solved? Sometimes single stepping is used. This is when a system can be run just one step at a time until the problem is found