The Code-and-Fix Model. The basic model used in the earliest days of software development contained two steps

2. Fix the problems in the code. | Thus, the order of the steps was to do some coding first and to think about the requirements, design, test, and maintenance later. This model has three primary difficulties: (a) After a number of fixes, the code became so poorly structured that subsequent fixes were very expensive. This underscored the need for a design phase prior to coding. (b) Frequently, even well designed software was such a poor match to users' needs that it was either rejected outright or expensively redevelopment... | p. 61-62