"During the early phase of software development the documentation is the specification and is the design... If the documentation is bad the design is bad. If th

"During the early phase of software development the documentation is the specification and is the design... If the documentation is bad the design is bad. If the documentation does not yet exist there is as yet no design, only people thinking and talking about the design which is of some value, but not much." "During the testing phase, with good documentation the manager can concentrate personnel on the mistakes in the program. Without good documentation every mistake, large or small, is analyzed by one [person] who probably made the mistake in the first place because [they are] the only [person] who understands the program area." "Following initial operations, when system improvements are in order, good documentation permits effective redesign, updating, and retrofitting in the field. If documentation does not exist, generally the entire existing framework of operating software must be junked, even for relatively modest changes." All quotes from "Managing the Development of Large Software Systems" by Winston Royce, 1970. All quotes perfectly match my experience working on projects that were developed using contemporary low-documentation agile development methods.