Why are unforeseen problems accumulating at the end of the case, in spite of the efforts made by the project management office to anticipate and contain them?

Learning Goal: I’m working on a supply chain question and need an explanation and answer to help me learn.
ASSIGNMENT
The PCNet Project
This case describes a large and complex IT integration project after the acquisition of one mining company by another. As part of the integration, 40,000 PCs, computer applications and the network had to be consolidated into one system. The project lasted two years and involved 1,000 people across the organization. The case illustrates how the different components of Project Risk Management are carried out in practice.Questions1. Why are unforeseen problems accumulating at the end of the case, in spite of the efforts made by the project management office to anticipate and contain them?
Requirements: 200