A new two-layer optimization scheme is presented for operating procedure synthesis in the presence of quantitative safety path contraints. Layer 1 optimizes the overall operations time by varying the "operator time: constant"-the time that an operator is applied to the system. Layer 2 performs the path-constrained optimization by minimizing the sum-of-squared errors between the current system state vector and a prespecified goal state vector by applying the system operators. New system states are calculated using dynamic simulation of the equations describing the system. A detailed example involving mixture control of potentially flammable chemicals is described, illustrating all aspects of the proposed methodology.