No, hard no. In my experience good communication solves this every time. MGMT: We need an estimate ENG: I have several unknowns MGMT: We really need an estima

No, hard no. In my experience good communication solves this every time. MGMT: We need an estimate ENG: I have several unknowns MGMT: We really need an estimate ENG: This is my rough estimate, but be aware that the unknowns could change this drastically MGMT: Ok, what do you need to get a firmer estimate. And so on. As a project progresses, the communication between ENG and MGMT is crucial to ensure that MGMT are aware how those unknowns are affecting the project, MGMT will decide at every juncture if the project is worthwhile to continue to invest resources into it (assuming they avoid the sunk cost fallacy)