The learning objectives for this chapter include: To explain how an iterative, incremental development process leads to faster delivery of more useful software, to discuss the essence of agile development methods, to explain the principles and practices of extreme programming, to explain the roles of prototyping in the software process. | Rapid software development Objectives To explain how an iterative, incremental development process leads to faster delivery of more useful software To discuss the essence of agile development methods To explain the principles and practices of extreme programming To explain the roles of prototyping in the software process Topics covered Agile methods Extreme programming Rapid application development Software prototyping Rapid software development Because of rapidly changing business environments, businesses have to respond to new opportunities and competition. This requires software and rapid development and delivery is not often the most critical requirement for software systems. Businesses may be willing to accept lower quality software if rapid delivery of essential functionality is possible. Requirements Because of the changing environment, it is often impossible to arrive at a stable, consistent set of system requirements. Therefore a waterfall model of development is impractical | Rapid software development Objectives To explain how an iterative, incremental development process leads to faster delivery of more useful software To discuss the essence of agile development methods To explain the principles and practices of extreme programming To explain the roles of prototyping in the software process Topics covered Agile methods Extreme programming Rapid application development Software prototyping Rapid software development Because of rapidly changing business environments, businesses have to respond to new opportunities and competition. This requires software and rapid development and delivery is not often the most critical requirement for software systems. Businesses may be willing to accept lower quality software if rapid delivery of essential functionality is possible. Requirements Because of the changing environment, it is often impossible to arrive at a stable, consistent set of system requirements. Therefore a waterfall model of development is impractical and an approach to development based on iterative specification and delivery is the only way to deliver software quickly. Characteristics of RAD processes The processes of specification, design and implementation are concurrent. There is no detailed specification and design documentation is minimised. The system is developed in a series of increments. End users evaluate each increment and make proposals for later increments. System user interfaces are usually developed using an interactive development system. An iterative development process Advantages of incremental development Accelerated delivery of customer services. Each increment delivers the highest priority functionality to the customer. User engagement with the system. Users have to be involved in the development which means the system is more likely to meet their requirements and the users are more committed to the system. Problems with incremental development Management problems Progress can be hard to judge and problems .