Investigating the relationship between project constraints and appropriate iteration length in agile development through simulations

Agile development is aimed at minimizing overall risk and encouraging rapid and flexible response to specification changes by using an iterative process. Despite its iterative feature, studies on the effects of iteration length have been lacking. Currently, there is no established method to quantitatively determine the appropriate iteration length, and abortion of projects with an inappropriate iteration length has been reported. We therefore create a model of agile development that focuses on iteration length, and propose a method of simulating a particular project to estimate the appropriate iteration length. Furthermore, we simulate diverse situations using various parameters to understand the relationship between the iteration length and project constraints. Our results show that the appropriate iteration length depends on the condition of the project constraints; the larger the amount of uncertainty, the shorter the appropriate iteration length, while the higher the complexity of the project, the longer the iteration length should be.