1. A therapy delivery system for an individual comprising: a therapy dosage module comprising an operating control system having an open architecture which supports operation of the therapy delivery system and which has a first control algorithm replaceable with a second control algorithm customized to needs of the individual, the first and second control algorithms being defined to determine therapy for the individual, wherein the open architecture of the operating control system provides a logical separation of the first and second control algorithm such that the first control algorithm is removable from the operating control system and replaceable by the second control algorithm without interfering with an operational functionality of hardware or software of the therapy delivery system; and a simulation module providing a test environment which simulates at least one or more physiological conditions of the individual and enables testing of the second control algorithm when implemented in the therapy dosage module in the test environment before being used in the therapy delivery system to deliver the therapy determined by the second control algorithm to the individual, wherein: the testing of the second control algorithm in the simulation module comprises using the second control algorithm on a virtual patient population of the test environment, and identifying any detrimental outcomes to patient health in the virtual patient population caused by the therapy determined by the second control algorithm prior to usage in the therapy delivery system to deliver therapy to the individual; wherein the therapy dosage module comprises a failsafe module defining one or more therapy limitations independent of the first and second control algorithms which prevents delivery of therapy outside of the therapy limitations.