This topic remains relevant in innovation management journals and innovation studies, however I see some scholars apply it without distinction. I wonder if there are any disciplinary differences between the terms.
I would say they are interchangeable. However, two people using the same term, be it FFE or FEI, sadly also do not necessarily mean the same by it. I think depends on the discipline, but also institutions where authors come from.
Thanks for your answer Renee. Now I understand both terms can be interchangeable. On your paper "Greening the Design Brief" yo mention the term FEI as an initial stage of a design brief in an innovation process, However I will like to know which is your point of view in the relationship between FFE, and specifically knowledge networks with the development of design briefs ? In other words, does FFE processes and dynamics can define information and scope contained in a design brief ?
As mentioned by Renee Wever, FFE and FEI are interchangeable terms. They both typically involves three core activities (i.e.,Opportunity Identification and Analysis, Idea Genesis and Selection, Concept Development). But FFE is preferably used to FEI, where process uncertainty exists, as Fuzzy front end is less structured and more opportunistic than formal developmental phases. Though its not a compulsive rule to use FFE, depending upon the school of thinking researches interchange terms FFE and FEI.