Tendering Phase Modeling
In this phase the contracting authority publishes initial information about a public contract. This includes basic information, e.g., contract title, description, and the reference number assigned to the contract by the authority (which is usually unique only in the scope of the authority itself). If the contract is too large or too complex, the authority can split it into two or more sub-contracts, which are called lots. Each lot is a contract on its own but it is a part of its parent contract. In the ontology, lots are represented using the class pc:Contract. A lot is associated with its superior contract via the property pc:lot.
The authority also publishes basic information about itself, e.g., its legal name, oﬃcial number or contact information. An important piece of information is the so-called buyer proﬁle, which is a web page where the contracting authority publishes information about its public contracts.
Moreover, the authority publishes various requirements and restrictions on the contract. The restrictions include the speciﬁcation of the kind and objective areas of the contract (Supplies, Works and Services), deadline for tenders, time to realize the contract (in a form of estimated end date or required duration in days or months), estimated price and non-structured speciﬁcation documents. The objective areas restrict potential suppliers to only those operating in the objective areas. The authority also speciﬁes the procedure by which an awarded tender will be selected from the received tenders. We consider the following procedure types in the core, which are primarily deﬁned by the EU legislation but can be applied world-wide: Open, Restricted, Accelerated Restricted, Negotiated, Accelerated Negotiated, and Competitive Dialogue.
The requirements include two kinds of information. First, the authority speciﬁes the items (i.e., products or services) that constitute the contract. The ontology reuses the class gr:Offering to represent items. Basically, the items are characterized by their name, description and price, but other kinds of characteristics can be used as well, which we however do not cover in the domain model (e.g., references to various product or service classiﬁcation schemes). Second, it speciﬁes a combination of award criteria. The class pc:AwardCriteriaCombination is the representation of this feature in the ontology. For each award criterion, expressed in the ontology using class pc:WeightedCriterion, a textual description (or, we can say, name) and weight percentage of the criterion is speciﬁed. Usually, a speciﬁc combination is distinguished. For instance, it may specify that tenders are only compared on the basis of the price oﬀered and that the tender oﬀering the lowest price has to be selected.
After the authority receives the tenders, it publishes either the number of tenders or details of each particular tender received. For each tender, details about the tendering supplier and the oﬀered price are published. A tender may also comprise information about particular items (similarly to contract items, i.e. products or services) oﬀered. Tenders are represented in the ontology using a class called pc:Tender. Then, according to the award criteria, the authority selects and awards the best tender. In this stage, the authority publishes the date of the award and marks the selected tender as the awarded tender.
During the tendering phase, the contract can be cancelled by the authority.
If so, the authority publishes the date of cancellation.
Pre-realization, Realization and Evaluation Phase Modeling
In the pre-realization phase, the contracting authority signs an agreement with the supplier and publishes the agreement on the Web. The agreement is a non-structured text document. The ontology reuses the class foaf:Document to represent unstructured textual documents. We only consider one particular structured information published – the price agreed by both the authority and supplier. The agreed price should be the same as the price oﬀered in the awarded tender but it can diﬀer in some speciﬁc cases.
After the realization, the authority evaluates how the supplier fulﬁlled the requirements. This includes various sub-processes that we do not cover in our analysis. We are only interested in the actual end date and the actual ﬁnal price of the contract. Moreover, the authority could cover the price of the contract or its part by subsidy from an external source (e.g., EU structural funds). Subsidies are usually provided in the form of one or more payments to the authority.