About 6 months ago when I worked in validation, mw group worked on a project where we did a media simulation in collaboration with the manufacturing department. There were one other group managing that project and it was the first time we were performing it with this group. In the initiation phase the group got together and determined what needed to be accomplished and the time line for our deliverables. We planned out how we can meet our goal be determining a schedule for the performers and what resources and documentation we would need. In our case that part went reasonable well, until we got to the execution phase where we realized that that we did not account for human error in the planning phase. Working on project with manufacturing require that we follow GmP with no exceptions. We outsourced another company to check all the samples that were filled into vials to verify that the sterility requirement was meet. We ran into a lot of problem with the consistency on the labels and the documents that were going to the other company being correct. This was due to a lack of communication between departments and resulted in some delayed in the project. Once we realized this we went back to the planning and was able to get back on track.