Mark Last

This discussion paper addresses combinatorial models in system testing from the perspective of system usage (utilization) and corresponding examination of system functions and their groups. Thus the following aspects of multi-function system testing are under study: analysis of system requirements and revelation of atomic system functions and their relationships, analysis of system function groups (clusters), design of the most important test inputs and sequences of the test inputs. The basic combinatorial problem is: composition of the best (the most important) test input(s) for each group of atomic system functions. Additional combinatorial problems are the following: (a) design of test input sequence for a trail (chain) of function clusters, (b) design of collection of test input sequences as covering of function cluster digraph, (c) structural fusion of unit test results. Numerical and real world examples illustrate the proposed approach.