Why it’s important to protect cells in Excel
If you create an Excel report for someone, it is important that you somehow visualise which cells they are allowed to change, and which cells they should not touch. The common way to do this is to use a blue font for the assumptions, i.e. the values that can be changed.
Unfortunately, this is not always enough. Inevitably, someone will try to enter values into the calculation cells as well, and when they do, the whole report might be useless. We need to protect the cells from being tampered with, and the good news is that it takes less than a minute!