Distributed techniques in software systems integration

Many aspects of software development use varieties of distributed computing techniques. We focus on a specific phase known generally as testing but more appropriately as iterative test and integration. Traditional software development is mandated by methodologies. These methodologies follow from the waterfall model of software development, and provide automation support via software tools for coding, documentation analysis and evaluation. Quality and productivity have become the driving forces and this in turn emphasized modularity, reusability and use of formal methods where possible. The traditional waterfall model of software development partitions the processing sequence into phases of requirements, specification, design, implementation, and testing and validation. While this is still the basic conceptual model used in most of the development methodologies, this does not explicitly include the feedback and revisions between phases due to errors, problems, omissions and changes. Also it does not include the process of integration that takes place at every step and most importantly in the later stages namely, iterative testing and integration. We discuss our approach to the system integration problems which are outlined. The system integration process mainly depends on (a) a formal methodology that leads to an efficient integration testing plan, and (b) a consistency checking mechanism that validates the module subsystem interfaces and intermodule interactions during all the changes of the integration testing process. The integration plan that is produced should be good in the sense that the scheduling and partitioning of a collection of modules to be integrated should be done to reduce the interactions and dependencies between program units as modifications are made at the different phases of the development and assist in localizing errors during integration testing. We investigate issues in the generic integration lifecycle including properties that individual software modules should possess for efficient integration and guidelines for designing modules.