Method for using sensitivity analysis to inform the design and performance of a well test are provided. In one embodiment, a method includes providing a reservoir model of pressure transient behavior and performing a sensitivity analysis to identify an input parameter of the reservoir model that can be estimated from pressure transient test data collected from a well location. This method also includes using the results of the sensitivity analysis to design a pressure transient well test for measuring the identified input parameter. Other methods and systems are also disclosed.