I have had a a few experiences in which completion of projects have been delayed, I was validated a new piece of lab equipment, during the validation process i ran into delays ranging from the acquisition of testing equipment to approvals from R&D with regards to process. My project manager knew the potential in delays because this new equipment offered a higher level of resolution, as a result we had to also update the applicable references then train all operators on the new equipment. In order to address these issues and statuses on the project, my manager has weekly one on one updates in order to address the issues find solutions for the underestimation of project timelines.
Chris