For increasing user control and insight into preparing a mixed semiconductor design specification for simulation, there are provided methods responsive to commands that provide control over resolution of disciplines and partitioning of the design into analog and digital portions. In some aspects, the methods provide block-based assignments of disciplines, as well as design partitioning. In other aspects, the methods provide for resolving a discipline to apply in a block from among multiple possible disciplines. In some aspects, error flagging may be available for detecting disciplines different from what provided for assignment in a block. Assignments may be indicated based on instance, cell, terminal, or library names and may be specified with wild cards. In still other aspects, the methods may be embodied by instructions on computer readable media, and in systems comprising general and special purpose computer hardware that may communicate with various storage facilities and over various networks.