Modelling of industrial processes is simplified with the use of Mixed Logical Dynamic (MLD) framework. Optimal control problems can be generated for application to industrial processes. For example, two arbitrarily connected MLD blocks are automatically merged to obtain one composite MLD block. Via a repeated use of the procedure, any arbitrarily complex system containing the complete description of an industrial process can be generated from the simplest MLD building blocks. The optimal control problem is generated via adding an MLD block whose unique output becomes the cost functional of the problem. In a graphical environment, any specific industrial process may be reproduced by instantiating blocks from a library of basic MLD elements or atomic MLD blocks and by properly connecting them. In case an appropriate library is available, this process will not require any expert knowledge from the end user apart from the ability to build the graphical interconnections mentioned.