If two tasks have a resource conflict $($i$.$e$.$ both must be completed by the same person and cannot be completed at the same time$),$ how should a PM decide which to schedule first and which to move to a later date?

One way to minimize resource conflicts is to organize resources into pools, groups of resources who are interchangeable in scheduling. For example, instead of having Professor David and Professor Lu each available $40$ hours$/$week$,$ you could have a pool called "Professors" available for $80$ hours$/$week$.$ What are the advantages and disadvantages of this approach?

What are some of the barriers to implementing critical chain concepts in the real world?