How important is the constructability and operability review of a design package? What it avoids?

It is very important to make sure that in constructibility that a review of all what has been put in the planing and design phase has been met in the construction while having done so for sure it will reflect on the operability that everything it has been designed and build for to do it functioning & performing and able to achieve the purposes. This will avoid having a any defaults, delays, market decline, share drop, reputation and so on, losses and so on.