e3value user manual, first release

5.8 Valuations of a value transfer

Each value transfer has a monetary value for the actors involved in a transfer. For the transfer of money, this value is fixed: If I give you f10, then you receive f10. For the transfer of other value objects, the value of the object differs per actor.

All ports and transfers have a Valuation property that can be set. Its default value is undefined.

5.8.1 Money transfers

The amount of money transfered between actors is specified as Valuation at one of the ports or at the transfer itself. The Valuation of ports and value transfers is by default undefined. If an actor determines the price, we set the Valuation property at the port of that actor. During analysis the editor checks that the valuation of the port at the other end is undefined.

If the two actors agreed on a price, we set the Valuation property of the transfer. If the Valuation is specified for a transfer, this overrides any value specified at a port of the transfer.

Figure 5.8:Two ways to specify how much is money is paid.

For example, figure 5.8 shows a business Traveler who negotiated a price of f190 for a Train trip and a power Traveler forced the Railway company to accept a price of f180. The powerless Traveler pays the standard price of f200 set by the Railway company.

5.8.2 Non-money transfers

Non-money objects may have a different value for different actors. For example, in the market scenario in figure 5.9, the Traveler and the Railway company assign different values to non-money objects. For the Traveler, the valuation measures the increase in utility by consuming the value object, for the Railway company the valuation measures the cost of producing it.

Figure 5.9:Adding valuation for non-money transfers.