The thesis describes operation and execution of program made for three operator cells, that are part of a production line composed of thirteen cells. Line is built for the purpose of automatic LCD display assembly and is made as a project in the INEA company. Thesis consists of work on that line that was in my personal domain. Two seperate parts of the program are described: a program of programmable logic controller and a program of human-machine interface. Both of them are written in Siemens TIA portal v15 programming tool. The first part of the thesis presents a part of the production line that concerns the three operator cells, with a brief description of equipment used in them. The following chapters present the program itself, starting with the part for programmable logic controller. Mainly, the program is written in ladder diagram, only a few parts are written in structured text programming language. In the finishing chapter, design and functionality of the human-machine interface is described.