Top-down and bottom-up design Bottom-up design Make decisions about reusable low-level utilities Then decide how these will be put together to create high-level constructs A mix of top-down and bottom-up approaches are normally used: Top-down design is almost always needed to give the system a good structure Bottom-up design is normally useful so that reusable components can be created www.oseng.com O Lethbridge/Laganiere 2001 Chapter 9: Architecting and designing software© Lethbridge/Laganière 2001 Chapter 9: Architecting and designing software 11 Top-down and bottom-up design Bottom-up design • Make decisions about reusable low-level utilities. • Then decide how these will be put together to create high-level constructs. A mix of top-down and bottom-up approaches are normally used: • Top-down design is almost always needed to give the system a good structure. • Bottom-up design is normally useful so that reusable components can be created