Multilevel Flow Modeling

MFM originated as a modeling language for capturing how human operators identify and handle unknown operation situations in order to improve the design of human-machine interfaces. == Syntax ==

File:MFM concepts.png|thumb|MFM concepts for functions and relations • Direct influence is the effect of a transport taking in mass or energy from the upstream function and passing it on to the downstream function. • Indirect influence, on the other hand, is derived from different physical implementations and represented by influence or participate relation of another function toward the transport. The state of transport can be affected e.g. by an abnormal state of influencing downstream storage, while the state would not be affected by a participating one. According to the underlying physical interpretation inference rules for all possible patterns of flow functions have been established. Zhang compiled these patterns and the implied causality. == Example ==

The MFM diagram of a heat pump reflects the overarching objective (cob2) of maintaining the energy level on the warm side constant. The energy flow structure efs2 shows the system function from the most prevalent (energetic) perspective which is further decomposed in the mass flow of coolant (mfs1) as the means for the desired energy transport. Further hierarchical analysis produces efs1 that represents the energy needed for the pump as a means to produce a part of the mass flow. The operational constraints introduced by control systems such as a water flow controller are modeled by cfs1 and a temperature controller cfs2. == Application ==

MFM based solutions for many aspects of industrial automation have been proposed. Research directions include: • Plant wide diagnosis • Alarm Management • Risk Assessment • Automatic procedure generation == References ==