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User’s guide to ePO example 1: Who buys what from whom?

Before reading this example, please visit the Conceptual Model and Glossary guides.

Lets translate that question to a query that aims to connect the buyer with the lot, and the winner of the tender award outcome, that was awarded that lot.

The question we are addressing is quite general, so we need to make it more specific.

To build this query we need to connect the name of the buyer with the Lot, and then find the winner of the tender award outcome.

  • First we need to locate the Buyer class in the ePO core conceptual model (Fig.A1):

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Figure A1: epo:Buyer in ePO core.

  • Now we need to find an attribute to identify that buyer. Searching the glossary for the attributes of epo:Buyer does not yield a suitable attribute, so we need to look for another class that is a generalisation of epo:Buyer.

Searching the ontology, we find the role hierarchy diagram (Fig.A2), and decide to use the dct:title attribute of class epo:AgentInRole, which is a generalisation of class epo:AcquiringParty, which in turn is a generalisation of epo:Buyer.

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Figure A2: epo:Buyer can use the dct:title attribute of epo:AgentInRole as it is connected to it using generalisation relations.

  • Next step, is to find a connection between the buyer to the Lot through the tender award outcome. To do this we use the award decision outcome relations diagram (A3).

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Figure A3: Connection from epo:Buyer to epo:Lot using the award decision outcome relations diagram

  • Now we need to find a connection between epo:Winner and one of the concepts we already visited. As seen in figure A4, there are 2 connections to epo:Winner from the classes we already visited on the the award decision outcome relations diagram

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Figure A4: We can connect to the epo:Winner class from epo:Lot via the epo:Tender and epo:TenderAwardOutcome classes or from epo:AwardOutcome through the class epo:TenderAwardOutcome.