Iterative and incremental development

Iterative and Incremental development is any combination of both iterative design or iterative method and incremental build model for development. There are two approaches, evolutionary and single step , to full capability. An evolutionary approach is preferred. … approach, the ultimate capability delivered to the user is divided into two or more blocks, with increasing increments of capability...software development shall follow an iterative spiral development process in which continually expanding software versions are based on learning from earlier development. It can also be done in phases. Iterative and Incremental development is any combination of both iterative design or iterative method and incremental build model for development. The usage of the term began in software development, where the combination of the two terms iterative and incremental has been long standing, and has been widely suggested for large development efforts. For example, the 1985 DOD-STD-2167mentions (in section 4.1.2): 'During software development, more than one iteration of the software development cycle may be in progress at the same time.' and 'This process may be described as an 'evolutionary acquisition' or 'incremental build' approach.' In software, the relationship between iterations and increments is determined by the overall software development process. The basic idea behind this method is to develop a system through repeated cycles (iterative) and in smaller portions at a time (incremental), allowing software developers to take advantage of what was learned during development of earlier parts or versions of the system. Learning comes from both the development and use of the system, where possible key steps in the process start with a simple implementation of a subset of the software requirements and iteratively enhance the evolving versions until the full system is implemented. At each iteration, design modifications are made and new functional capabilities are added.