Software as a Pegboard Set
Software is not like traditional engineering disciplines. Unlike a bridge whose requirements are essentially set in stone, software requirements consistently change and evolve with the needs of the business. The requirements, of say civil engineering, are more firm and concrete than that of software engineering because the artifacts that are being constructed are usually large physical objects like a road or bridge. In the other hand, software is malleable and it often refactored easier than business constraints, that is why product managers often prefer to wedge a round peg (software) into a square hole (requirements) as business constraints evolve. But unlike a kid’s shape sorter or pegboard set, the peg and the hole are consistently changing and not always into the same shape.