Flow analysis

Flow analysis is an analytical tool that identifies disadvantages in flows of energy, substances, and information in an engineering system.

Overview

Flow analysis compliments function analysis by identifying disadvantages that may not have been revealed through it.

There are three types of flows analyzed during the analysis:
1. substance flow,
2. energy flow, and
3. information flow.

Modeling the engineering system as flows of substance, energy, and information provides an alternative view of the system.

The flows go through their channels, which are the system’s components. That’s why function analysis must be completed prior to flow analysis.

Flow analysis can be conducted for both devices and processes. In either case, the outcome is a list of flow disadvantages. Together with function disadvantages, they can be used as building blocks in cause-effect chain analysis.

Stages of flow analysis

There are two major stages of flow analysis. These are as follows:

  • flow partition analysis during which the allocations of flows are identified,
  • flow modeling during which the flow model is created (e.g., in a graphical form), and specific flow disadvantages are identified from the list of typical disadvantages.

Algorithm

  1. Select the type of flows for analyzing.
  2. Create the first flow channel:
    • indicate the components through which the flow is flowing (the outcome of the component analysis can serve as the basis for that, but if needed you should split the components into more granular ones (recommended));
    • connect those components.
  3. Moving along the channel, identify as many flow disadvantages as possible. Use the list of typical flow disadvantages for that.
  4. Perform the similar actions for other flows.
  5. Compose the general list of flow disadvantages to use as an input to CECA together with the list of function disadvantages.
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