Since the very beginning, approach to control system design is being changed and improved. As the technology advances, demands on such a system become tougher, making the system's capabilities even higher. As a consequence, some international standards have been developed, covering programming languages, design approaches, naming conventions etc. This paper presents the main characteristics of modern industrial control systems. It focuses on programmable logic controllers (PLC) and Supervisory, Control And Data Acquisition (SCADA) systems, as a foundation of an industrial control system. The existing system controlling the tobacco stem processing line in Tobacco factory Sarajevo will be analyzed and some failures and unused potential recognized. The paper gives ideas/suggestions about how to improve this or a similar control system.