Object modeling organizes knowledge about design components and analyses in a modular fashion, from which representations of candidate designs may be quickly constructed. Modeling flexibility requires complimentary flexibility in analysis. Constraint propagation is a least-commitment approach to performing computations, since dependencies between calculations are inferred at run-time; it is thus well-suited to managing parametric analyses for conceptual/preliminary design as candidate configurations are evaluated and modified. A modeling package that combines these two approaches has been implemented. Classes for describing both design components and design analyses can be specified in terms of attributes and constraints on these attributes. A third type of class, called a link, is used to specify constraints on the attributes of other objects, referred to as its linkages. Candidate designs are modeled by instantiating classes representing the components to be combined, the analyses to be performed, and the links among them. As attribute values are assigned by the user, constraint propagation is triggered to run analyses and transfer results among the instances. Discussion focuses on implementation of this approach, and its application to sample problems in the design of aircraft engine turbomachinery and exhaust nozzles.