One of the methodologies utilized for process design consists of the application of optimization techniques to identify the best design inside a set of alternatives. In spite of the efforts and advances, this approach is not broadly utilized in the industrial practice. One reason is that their implementation requires a good knowledge of the mathematical programming techniques. Therefore, it is important to develop procedures that can consider real situations, but on the other hand does not require complex mathematical methods. In this work the potential application of grey programming (GP) and grey-system theory to heat-exchanger network design is analyzed. GP is a simple technique to consider uncertainty. Complete methodologies are developed, which include the grey composite curve, the determination of the grey minimum utility consumption, and determination of grey number of exchangers units. The utilized techniques involve grey linear programming (GLP) and grey mixed-integer linear programming (GMILP)