Computer systems have become essential to the engineering, operations and maintenance activities of water supply systems. In the past, computerized islands of information and technology have been the norm. Today, there is an increasing expectation that key computer systems share data and work together seamlessly to leverage one another's benefits. Because of advances in computer software and hardware, the fundamental technology now exists for such systems to be built and productively used. This paper outlines some of the technical considerations related to building stand-alone, interoperable software components with current technology in mind. Software componentization standards such as COM and COBRA are discussed. Various considerations, including software design practices, networking capabilities, and application programming interface provisions, influence the design of a software component and its portability and usefulness. The relative importance of these issues to the ultimate usefulness of the software component are considered. The experiences of an implementation team increating a hydraulic network simulation component are described. Some of the paybacks from the effort of building flexible components are outlined and demonstrated, including script-driven sessions for batch simulations and control logic, and ease of assembly with other systems. Includes 3 references, figures.