If you are interested in more in-depth information on Multilevel Flow Modeling, you can start with the publications below.
An overview of Multilevel Flow Modeling (requires login) - Morten Lind
An introduction to Multilevel Flow Modeling - Morten Lind
Control functions in MFM: basic principles - Morten Lind
Reasoning about Causes and Consequences in Multilevel Flow Models (requires login) - Morten Lind
Consequence Reasoning in Multilevel Flow Modelling - Morten Lind, Xinxin Zhang, Ole Ravn
Multilevel flow modeling of Monju Nuclear Power Plant - Morten Lind, Hidekazu Yoshikawa, Sten Bay Jørgensen, Ming Yang, Kiyoshi Tamayama, Kyoichi Okusa