  Procurement refers to a process resulting in delivery of goods or services
within a set time period. The process includes aspects of purchasing,
specifications to be met, and solicitation notifications as in the case of
Request For Proposals (RFPs). Typically such an RFP is described in a verbal ad
hoc fashion, in English, with tables and graphs, resulting in imprecise
specifications of requirements. It has been proposed that BPMN diagrams be used
to specify requirements to be included in RFP. This paper is a merger of three
topics: (i) Procurement development with a focus on operational specification
of RFP, (ii) Public key infrastructure (PKI) as an RFP subject, and (iii)
Conceptual modeling that produces a diagram as a supplement to an RFP to
clarify requirements more precisely than traditional tools such as natural
language, tables, and ad hoc graphs.
