The Project Management Institute's A Guide to the Project Management Body of Knowledge (PMBOK Guide) lists the four initial (pre-execution) processes of procurement as: Procurement Planning, Solicitation Planning, Solicitation, and Source Selection1. The inputs to Procurement Planning include the project scope statement and information on available resources and market conditions, and are used to drive a build-or-buy analysis, which results in a procurement management plan and a Statement of Work (SOW). The SOW is used as input to the Solicitation Planning process, during which a Request for Bid or RFP-like document is developed to elicit vendor proposals, in addition to the criteria to be used to evaluate vendor responses or software1. Therefore, even in the case of urgency, it is important for the project manager to follow the company's standard vendor selection criteria process to ensure the selection of a reputable vendor that can meet the project's needs. References:
https://www.pmi.org/learning/library/vendor-selection-process-predictor-project-success-8514