First, the subject is missing, which means that it could be any one of a number of pronouns or nouns, but the assumption--given that you are the one writing the journal entry--is that you, the writer, met with supervisors of the following departments, Quality Control, Production, and Research & Design. Second,
Originally Posted by dtharachai
this here, The noun supervisors can't be the subject, because it's part of the verb's object; I met with supervisors.
Met with QC, Production and R&D supervisors... also means this,
Met with supervisors... and this,
Met with supervisors from Quality Control, Production, and Research & Design...
Lastly, to discuss is a verb, but not the main verb. Its subject is implied, either we or I,
(I) met with QC, Production and R&D supervisors [in order] to discuss (so that we, together as a group, could discuss / so that I could discuss with them) [the] new Shrimp Wonton order for [the] Korean customer.