Although manufacturing plants dedicated to a singleproduct exist, most plants today make multiple products. Thepressure to compete via product variety and customization hasserved to increase the number of different products produced bya typical plant. The manufacturing systems of complex maketo-order families of products usually face problems associatedwith the high variability of processing times, supply deliveriesand market demand. How can product design improve theperformance of the manufacturing system of complex make-toorder products? In this paper we present a method, based onrobust design principles and a multi-objective decision modelembodied in the Robust Concept Exploration Method, tosupport concurrent decisions in the early stages of the design ofmake-to-order families of products. Emphasis is given toadopting standardization, modularity and robustness in productdesign as key principles to improve the performance of this kindof systems. The design of an absorber-evaporator module for afamily of absorption chillers is used as an example to illustrateour approach.