O-O analysis is different form structural analysis in that it allows a system to be developed incrementally by building a series of prototypes and adjusting them to user requirements, whereas Structural Analyses otherwise known as the waterfall method uses a System Development Lifecycle (SDLC) to plan and implement an information system from the top down leaving little input from the end user. The waterfall method can become costly if magger reworks of the information system are required after the system analysis stage of the SDLC. O-O analysis allow for continual development using feedback from the end users.