Choosing a Software Development Methodology, can be as hard as planning a Thanksgiving dinnner for two families. Being able to decide which type of software methdology is best for the team and the project, means there many factors to take into consideration.
Is this a small web application or a large-scale enterprise application? This will help determine if an agile or waterfall methodology is more suitable.
Is the team familiar with the methdology? How much experience has each team member had with the methodology? Are the team members able to work within the time frame or are there any days off or special considerations that need to taken into account?