I am starting a new role as a Management Information tester. Can someone give me some beginners advice please. I keep hearing source and target? What exactly does this mean?
The actual testing you'll undertake will still depend on the requirements given, but the links above should point you in the right direction.
MIS is the use of information technology, people, and business processes to record, store and process data to produce information that decision makers can use to make day to day decisions.
Source to Target:
In layman's terms, S2T testing ensures that AAA (in your Source) is correctly mapped to AAA (in your Target), so when information is extracted, transformed, and loaded, the data is correct. The same applies to BBB, CCC, DDD, and so on.
This article on "Why Source to Target Mapping documents matter" might be useful to you, even though it's written from a developer's perspective.