Material flow network

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Material flow networks are a special model approach for mapping material flow systems in the context of a material flow analysis ( material flow management ). They are based on the methodology of Petri nets . The material and energy flows of a system (for example a manufacturing company) as well as their movements and transformations in production and reduction processes are modeled as a network.

Methodology of material flow networks

The methodology of the material flow networks is originally based on the methodology of Petri networks. In contrast to Petri networks, where the main focus is on synchronizing events, material flow networks are not event-related. Rather, material flow networks are about mapping and linking parallel material and energy flows and their quantitative interdependencies.

Material flow networks are able to map complex material flow systems that:

  • Create multiple products at both the process and system level
  • also take non-linearities into account at the process level
  • In addition to material flows, also consider stocks in the system
  • are based on a period-related accounting
  • can be evaluated within flexible balance sheet limits.

Elements of a material flow network

Analogous to the Petri networks, there are three basic system elements in material flow networks:

  • Transitions,
  • Make and
  • Edge.

Transitions are understood to be processes of conversion of matter within material flow networks, which can have a producing or reducing character. Places correspond to bearings and the edges form the links between transitions and places. In general, a transition can only be linked to one place, never directly to the next transition.

It is important that the transitions represent encapsulated models that can be described in a mathematically flexible manner. In this way, a high degree of flexibility in the modeling of material flow systems is achieved, since individual processes or transitions can be described with any complexity, depending on the task at hand. The possibilities for describing transitions range from the reproduction of pure input-output relationships, to complex mathematical systems, to the storage of further network structures (subnets).

Calculation of a material flow network

The calculation of a material flow network always refers to a time period. It does not matter whether it is a day and a whole year. The calculation itself has to be divided into two processes:

  • Calculation of the transitions (analogous to the switching process in Petri nets) and
  • Arithmetic of stocks and flows in the network.

Use of material flow networks

Material flow networks are u. a. an ideal basis for material flow-based cost accounting and special ecological assessment methods (e.g. UBA impact potential method, eco-indicator 95, CML method).

See also

literature

  • Möller, Andreas (2000): Fundamentals of material flow-based corporate environmental information systems. Project publishing house Bochum.

Web links