Before revision:  In this model, we say a policy leads to zero (asymptotic) queueing delay if the job delay under the policy approaches the delay given by the max of service times of its tasks , as if tasks entered service right upon arrival.
After revision:  In this model, we say a policy leads to zero (asymptotic) queueing delay if the job delay under the policy approaches the delay given by the max of its tasks' service times, i.e., the job delay assuming its tasks entered service right upon arrival.