New technologies and standards are emerging which will have a dramatic effect on the design and implementation of future industrial control systems‎.‎ PLCs and PC‎-based soft controllers are beginning to use software components‎,‎ such as object‎-oriented technology‎,‎ to bring together the hitherto different worlds of factory automation and business systems‎.‎ New tools and techniques are needed to design and model these systems‎,‎ such as UML and modern fieldbus technology‎.‎ The new IEC 61499 standard has been developed to model distributed control systems‎,‎ defining concepts and models so that software in the form of function blocks can be interconnected to define the behaviour of a distributed control system‎.‎ Tools based on IEC 61499 are likely to emerge soon to model‎,‎ validate and simulate the behaviour of complex networks of function blocks and it is expected that this standard will become key to complex distributed systems‎.‎