The system works under the preemptive discipline, i.e. an admitted high-priority customer immediately gets service upon his arrival either by getting an idle service unit or by occupying service unit being used by low-priority customers.
The idle processing units can be used as storage vessels, since any processing unit is, in essence, a storage vessel.
The rationale for the cloud based workload consolidation model is to switch off idle baseband units (BBUs) to reduce the overall network energy consumption.
The methodology presented in this paper deals with the minimisation of single contaminant wastewater by exploiting the inherent storage possibilities in idle processing units.
Consequently, in order to reduce idle time of units and to raise the efficiency of process, we have to make operation sequences of products in each unit different by considering the production route of each product.
As the company's press release at the time said: "This core data protection feature… dynamically recreates data in the free-space of an Isilon IQstorage cluster, eliminating the need for idle, additional storage units, servers or spare disk drives – dramatically reducing the cost and complexity of a customer's storage environment".
Unit is in operation/under repair/waiting for repair/unit is idle in subsystem A. Unit is in operation/under repair/waiting for repair/unit is idle in subsystem B. Proper maintenance planning plays a role in achieving high system reliability, availability and production output.
If the assets are not sold, Sunoco said it would "idle the main processing units" in July 2012.
In other words, these units remain idle for the major part of the time horizon, amounting to wasted return on capital investment.
The notations used in the formulation of the model are as follows: λ1: mean arrival rate of the units in idle state.
