Abstract: A method is provided for deriving software tests from use cases. Thereby an activity digram is used to represent the possible use case scenarios. The test case scenarios are derived by applying coverage metrics on the activity diagram. The activities of the diagram are matched with an appertaining test. A test idea document is produced from the test case scenario. System test scenarios are created by concatenating the test case scenarios to a walk-through of the system. The system test cases are further enriched with activities to ensure the test precondition and to verify the test case scenario result. A test design document is produced for the system test.

Abstract: A water treatment module (14) has a sedimentation compartment (20), into which water is introduced under high pressure. A filter or microsieve (1) can be provided upstream of the sedimentation compartment (20). Above the sedimentation compartment (20) there is located a flooded first fixed bed reactor (22) for microbiological denitrification, which is flowed through from below. The water travels by way of an overflow device (34) and a sprinkler system (36) through which dissolved nitrogen is stripped and oxygen enrichment from the air occurs, into a second fixed bed reactor (38) for microbiological denitrification. This is constructed as a drip device, and is flowed through by air in a chimney-like fashion. Below the second fixed bed reactor (38) is located a catch basin (44) with a drain (54).