# Temporalis strategy for dynamic LCA calculations¶

Dynamic LCI is solved using a LCA informed best-first graph traversal algorithm, in which the technosphere matrix is treated as a mathematical graph.

The result of this traversal is a timeline, i.e. a list of biosphere flows located in time. Specifically, for each element in the timeline we know:

- When it occurs
- What the biosphere flow is
- The amount of the biosphere flow
- What inventory dataset caused the biosphere flow

We can then construct different timelines e.g. of emissions of one biosphere flow or due to one or more process as well as of total emissions. To these timelines it is possible to apply dynamic or static characterization factors to create a timeline of total environmental impact over time.

## Comparison with ESPA¶

Didier Beloin-Saint-Pierre proposed an approach called enhanced structural path analysis, which uses power series expansion and convolution to propagate relative temporal differences through the supply chain.

In the language of graph algorithm, the ESPA approach (power series expansion) is a breadth-first search.