Iterative Development Model The traditional methodology for delivering software projects has been, for years, the "Waterfall Method". If project requirements are static or have been clearly stated from the beginning, then this method is useful. Typically, the software development lifecycle (SDLC) exceeds one year which leads to risks of the project being cancelled (according to the Standish Group, about 31% are cancelled before completion). An alternative approach is the Iterative Development Life Cycle (sometimes referred to as the Spiral Life Cycle). With the Iterative Life Cycle, analysis is done just the same as with the less frequently used Waterfall method. However, once analysis is done, each requirement is prioritized as follows: High - These are mission critical requirements that absolutely have to be done in the first release. Medium - These are requirements that are important but can be worked around until implemented. Low - These are requirements that are nice-to-have but not critical to the operation of the software. Once priorities have been established, the releases are planned. The first release (Release 1.0) will contain just the High priority items and should take about 1 to 3 months to deliver. Below are the advantages of the Iterative Life Cycle: The Design phase goes much faster, as designs are only done on the items in the current release (Release 1.0 for example). Coding and Testing go much faster because there are less items to code and test. If major design flaws are found, re-work is much faster since the functional areas have been greatly reduced. The client gets into production in less than 3 months, allowing them to begin earning revenue or reducing expenses quicker with their product. If market conditions change for the client, changes can be incorporated in the next iterative release, allowing the software to be much more nimble. As the software is implemented, the client can make recommendations for the next iteration due to experiences learned in the past iteration. Our experience has found that you should space iterations at least 2 – 3 months a part. If iterations are closer than that, you spend too much time on convergence and the project timeframe expands. During the coding phase, code reviews must be done weekly to ensure that the developers are delivering to specification and all source code is put under source control. Also, full installation routines are to be used for each iterative release as it would be done in production.