That stands for First Lot To Stock, meaning the first group of products being built and ready to ship to customers. In my experience, this date is always unrealistic and often changes multiple times during product development.
The date is always set leaving no room for problems to develop, as they always
I worked on a project last year that started in July. It was supposed to be one month long. The company hired a project manager that had worked for us some years ago but had left to raise her adopted daughter. She agreed to come back on a short term basis, about a month, to lead the development of this simple project. Well, after many changes, and much scope creep (one team member said that the scope of the project was growing faster than the national debt)it finally released at the end of January. Yep, that's a one month project that lasted 6 MONTHS!
I'm working on a manual now for a product that is due out in June. This product was formerly due out in February, March, April and May.
I'm willing to bet the doggone thing won't be out before the baby is born (October). But maybe that's just cynicism talking.
I'm working on the manual as though my deadline is June, but I'm not holding my breath.