Example systems and methods may allow for parallel operation of robotic devices within a workcell, such as industrial robots controlled to manufacture an output product. One example method includes receiving ordered sequences of operations for a plurality of corresponding robotic devices, determining time-based sequences of operations for each of the robotic devices, where a time-based sequence of operations indicates positions within the workcell at corresponding timesteps of a global timeline, determining one or more potential collisions involving the robotic devices that would result from parallel execution of the time-based sequences of operations within the workcell, modifying the time-based sequences of operations in order to prevent the one or more potential collisions, and providing instructions for parallel execution of the modified time-based sequences of operations at timesteps of the global timeline by the robotic devices within the workcell.