When making a decision it is human nature to make assumptions

This DB has three parts. 

1. When making a decision it is human nature to make assumptions. Understanding the assumptions along with the consequences should those assumptions be incorrect is important.  A best practice when making a decision is to make a list of any assumptions that exist.  Discuss a decision you have made in the past in your professional life that was based on assumptions that proved to be incorrect.  What were the consequences and how did you handle the resulting situation?
2. There are many different decision making models available such as: the rational model; the seven step model; and the Carnegie model to name a few.  What are the pros and cons of managers using decision making models? 
3. What factors should be taken into consideration when collecting data for a strategic decision?