The present invention provides a method and system for helping to improve processing duration and successful position determination in a position-determining system. The position-determining system receives a request to determine position of a mobile station, such as a cellular wireless communication device, and the request includes a timer value indicative of the maximum allowed time for responding to the request. The position-determining system then dynamically determines how long to spend attempting a primary location-determination process, based on the indicated timer value and an expected time necessary to employ a fallback, or secondary, location-determination process. If the position-determining system fails to determine the position within the time allocated to the primary process, it resorts to application of the secondary position-determination process. If either the primary or the secondary tier of location determination determines a position, that position is returned to the requesting entity; otherwise, a default or error message is returned.