A method for integrated development of multi agent PLC based control systems using IEC 61131-3 will be introduced. Dependability of technical plants will increase if control behaviour can be adapted during runtime. This is achieved by dynamic reconfiguration of faulty devices, e.g. sensors, at run-time. The replacement is based on analytical redundancy that is represented by a network of sensors and their interdependencies. This method supports the developer to sketch a suitable modular softwarearchitecture in regards to the hardware-architecture and the specific requirements of real-time and dependability. The integration of classical methods like fault-tree-analysis and graph-theory enables the developer to build a knowledge-based system so that the agents would have the ability to recognize faults, seize the needed actions within their scope and fulfil their goal. Recent investigations using a model-plant showed the feasibilities of this approach.