Throughout the Agile movement, one acronym that has been used in a derogatory way has been BDUF (Big Design Up Front). Essentially BDUF is when, at the start of a project (up front-UF), we do a big design (BD). The problem with BDUF is that we are laying out our entire plan when we know the least about our actual product. Agile is about doing a little, learning, doing some more, learning some more. It is about being incremental and iterative in our discovery, creation and learning.