An Experience in Testing an Object-Oriented Satellite Control System

This paper presents our experience in testing an object-oriented software: the Telemetry and Telecommand System (TMTC). The TMTC runs along a distributed architecture comprising microcomputers plus a Data Base server inter-connected via LAN under TCP/IP protocol. This in-house developed software was designed according to the Object Modelling Technique (OMT). TMTC's software components represent clusters of classes related to functionality and building blocks of generic services. In order to establish a systematic way for the testing activities we have adapted the Hierarchical Approach (HA), proposed by Shel Siegel, to the experience and culture of the team. The HA, focusing on object-oriented testing, has fitted well with the aim of detecting as many faults as possible in the early phases of the development. In the HA almost all classes are individually tested before being gradually integrated into groups. Groups of classes are defined according to the scenarios specified in the system design phase. This has considerably reduced the testing effort. This paper also discusses the system class number in comparison with the number of stubs and drivers generated for testing. The difficulties to test a distributed application for satellite controlling and monitoring are likewise examined.