Search in major vendor website
This is the most popular solution! However, it takes time to search and collect all necessary data. You end up with a BOM containing approximate descriptions for most of the components and for some MPNs or SKUs. Plus, it all requires manual entry in an Excel spreadsheet.
BOM Check, recommendation, design modification
At the end of the design stage, the R&D engineer will ask the purchasing team or the EMS contractor, to quote the BOM for prototype manufacturing purposes. This is where the headaches will start! First, looking for real components based on vague descriptions, taking advantage of the few MPNs provided all this to finally realize that some components are obsolete, have no inventory or require large MOQs!
Some component modifications may be required, deriving in design modification, and delays to the project schedule.