Critical chain is a schedule network analysis technique that modifies the project schedule to account for limited resources. Critical chain combines deterministic and probabilistic approaches. Initially, the project schedule network diagram is build using non-conservative estimates for activity durations within the schedule model, with required dependencies and defined constraints as inputs. The critical path is then calculated. After the critical path is identified, resource availability is entered and the resource-limited schedule result is determined. The resulting schedule often has an altered critical path. The critical chain method adds non-work schedule activities to maintain focus on the planned activity durations, also referred to as ______ .
A．duration buffers
B．resource leveling
C．reverse resource leveling
D．crashing