Water and energy are crucial aspects strongly connected when dealing with the problem of augmenting fresh water resources. Surprisingly, in the scientific and technological community there is a marked lack of attention to the combined research of water and energy issues. The present paper outlines a development-oriented object program in the said direction, oriented to the integrated analysis of power and desalination plants, which would hopefully fill the gap in having user-friendly software in the form of building blocks as an appropriate framework for the analysis, synthesis and design of either individual or integrated systems for energy and water. Such an approach would transcend other traditional approaches for process integration and obviously prove of great help not only to designers but also to researchers, educators and students. For illustrative purposes, in order to show the scope of the software being developed, an example is presented in which two different operation conditions of a dual-purpose power and desalination plant are compared. In particular, the effect of the throttling part of the steam extracted to the desalination unit is analyzed, which significantly increases the cost of water and electricity produced.