One of the challenges of successfully developing software using an agile software development methodology is the determination of which requirements or features to implement in which of the agile iterations. These decisions involve priorities, risk, development costs, and testing costs. Furthermore, initial decisions may have to be revised on the fly during development due to the possibility, embraced by the agile development philosophy, of changes to the set of requirements, and to the possibility of software failure during certain aspects of testing that require code fixes before further development can continue. With a sample project, this paper presents a heuristic method for scheduling requirements implementation in agile development iterations, taking into account all of the aforementioned considerations.