ATRAC has the capability to model the direct representation of the deregulated network's components through various company types:

Company Type	Characteristics
GTD	Generation, transmission, distribution company with dispatchable (variable) generation. Contains all of lines, load, generation.
GenCo	Generation-only company; no lines, no load. Can range from a single generator at a single site to multiple generators at dispersed sites.
TransCo (or RTO)	Transmission company; lines only, no load, no generation. Loss-following capability must be purchased from a GTD or GenCo with dispatchable generation. Facilities need not be contiguous within the network.
DisCo	Distribution company; load, lines, and fixed generation only, no dispatchable generation. Load/loss-following capability must be purchased from a GTD or GenCo with dispatchable generation. Facilities need not be contiguous within the network; a single company can be tied to multiple GTD's, GenCo's, or TransCo's at multiple locations. Can range from a single end user to a small subtransmission system.
Marketer	Non-facility company; no lines, no load, no generation.

Transactions can be scheduled between any company types, except transactions by a Marketer must balance to zero and transactions by a TransCo must balance to its internal losses.

Interchange of power over interconnected ties can occur between all company types except Marketers.

Dispatch of generation is calculated for GTD's and GenCo's to satisfy network transactions and load/loss-following requirements.

EXAMPLE

Assume G1, G2, G3 are GenCo's, with G2 serving as a centralized delivery/receipt point for generation sales and G3 having two separate locations. Assume T1, T2 are TransCo's. Assume D1, D2, D3, D4 are DisCo's, with D4 having two non-contiguous locations. Assume M1, M2, M3 are Marketers.

A typical transaction schedule could be:

G1 sells fixed Mw to G2 G2 sells fixed Mw to D1 G2 sells fixed Mw to M2 G3 sells fixed Mw to M1 M1 sells fixed Mw to G2 M2 sells fixed Mw to D2 M2 sells fixed Mw to D3 M2 sells fixed Mw to M3 M3 sells fixed Mw to D4 GTD sells fixed Mw to G2 GTD sells fixed Mw to M3 GTD sells fixed Mw to D4 T1 buys loss following Mw from G1 T2 buys loss following Mw from GTD D1 buys load/loss following Mw from G1 D2 buys load/loss following Mw from G3 D3 buys load/loss following Mw from G3 D4 buys load/loss following Mw from G3

The transaction schedule is then used to calculate interchange, generation dispatch, and power flows over the physical network.