Why don't information systems projects work out as planned? what causes the differences between the plan and reality?

Despite the fact that projects of this type are built from the reality and exposition of each organization, it is also true that during the march there are situations that had not been considered or that were classified as very unlikely to happen and that is when the project should consider them. Not only in projects of this type do discrepancies arise from what is planned vs. what is real, since no initiative of this type is exempt from atypical situations that could harm it. Although in some cases it is simply a lack of planning, in many of them the variable of atypical events that improve during the march influences.

answeraggressive behavior tactics include all of the above;