La electricidad y SOA

Rebuscando 'metáforas' de como explicar SOA ha aparecido esta. Me parece buenísima. En el texto además van apareciendo en cursiva los nombres de los elementos que se manejan en esta jerga del SOA. Aquí va:

The following example is taken from the SOA-RM specification and includes the principal concepts described above as well as other concepts that the Reference Model defines, in parentheses and italics:

• An electric utility has the capacity to generate and distribute electricity (the underlying capability). The wiring from the electric company’s distribution grid (the service) provides the means to supply electricity to support typical usage for a residential consumer’s house (service functionality), and a consumer accesses electricity generated (the output of invoking the service) via a wall outlet (service interface).

• In order to use the electricity, a consumer needs to understand what type of plug to use, what is the voltage of the supply, and possible limits to the load; the utility presumes that the customer will only connect devices that are compatible with the voltage provided and load supported; and the consumer in turn assumes that compatible consumer devices can be connected without damage or harm (service technical assumptions).

• A residential or business user will need to open an account with the utility in order to use the supply (service constraint) and the utility will meter usage and expects the consumer to pay for use at the rate prescribed (service policy). When the consumer and utility agree on constraints and policies (service contract), the consumer can receive electricity using the service as long as the electricity distribution grid and house connection remain intact (e.g., a storm knocking down power lines would disrupt distribution) and the consumer can have payment sent (e.g., a check by mail or electronic funds transfer) to the utility (reachability).

• Another person (for example, a visitor to someone else's house) may use a contracted supply without any relationship with the utility or any requirement to also satisfy the initial service constraint (e.g., reachability only requires intact electricity distribution) but would nonetheless be expected to be compatible with the service interface.

• In certain situations (for example, excessive demand), a utility may limit supply or institute rolling blackouts (service policy). A consumer might lodge a formal complaint if this occurred frequently (consumer's implied policy).

• If the utility required every device to be hardwired to its equipment, the underlying capability would still be there but this would be a very different service and have a very different service interface.

_soaelectric_