The process of making sound decisions is often difficult to master. The much larger perspective at the operational level requires a more complex and challenging decision-making process than at the tactical level. A campaign or major operation is conducted over a much larger part of the theatre and involves considerably larger and more diverse forces than tactical actions. The operational commanders need to evaluate the situation in all its complexity several weeks or even months ahead. Very often the commanders must make decisions without having all the information available. The resulting decision will often be made on incomplete and false information and in a time–space window very different from that of the tactical commanders. These decisions are more likely to be hypotheses, because they are based on several assumptions.