One of the biggest benefits of this model is task prioritizing. Each project can be divided into several tasks (features, used cases, tests, plugin dev. etc.). A Time & Materials project is billed based on the number of hours worked, nothing less or nothing more is billed. Highly suitable for projects when the in the situation that the requirement is not certain or might change. The hourly rate is fixed based on the project prospective based on forecasting the project outcome. One more important thing is that client can prioritize the order of features depending on their price and importance to the product solution and implementation.