Systems, apparatus, methods, and techniques of assembly of discrete modules of a control panel are disclosed. The modules can be independently wired, tested, and installed into a control panel. Module definitions are defined specifying components to perform the electrical function, a mechanical arrangement of the components, electrical connections, and logical interactions of the module. A bill of materials can be generated based on a designation of a set of modules for a control panel and the module definitions. Modularly assembled control panels are disclosed. An assembly frame is described herein for temporarily mounting components of a module for independent assembly of a control module and for eventual removal and installation into a control panel frame. The assembly frame may include a faceplate frame and side frames and temporary mounting features.