1. A method for targeted maintenance of computing devices in a system, the method comprising: assessing a maintenance request to determine a class of computing devices to which the request applies; selecting a propagation mechanism, from multiple propagation mechanisms, to apply to the class of computing devices based on multiple parameters, wherein said multiple parameters comprise an expected configuration of the class of computing devices and a previous success rate of one or more propagation mechanisms applied to the class of computing devices; generating an agent based on the propagation mechanism to carry out the maintenance request on the class of computing devices; wherein said generating comprises: instantiating an agent template and inserting custom code into the agent; configuring an agent lifespan, wherein the agent lifespan is the time period when an agent is actively executing on the class of computing devices; and configuring an agent propagation rate at which additional devices in the class of computing devices are targeted for propagation; deploying the agent on at least one computing device in the class of computing devices; and propagating the agent to additional devices in the class of computing devices; wherein at least one of the steps of assessing, selecting, generating, deploying, and propagating is carried out by a computer device.