You will seldom have perfect information about anything. You will never have perfect data about everything. More and better information will take more time and possibly money. We must come to grips with the question “how good is good enough?” Information is good enough when it does not disable us from arriving at a proper conclusion or decision. When you have reached the point where your information is adequate, it is a waste of resources to continue to seek more and better data - “gilding the lily”. The problem, of course, is in discerning when your information is adequate. The question to ask is, “how comfortable are we with making this decision based upon this information?” The sub-questions are 1) the importance of making this decision correctly and 2) our confidence in the information.
You will never have perfect information, but if you understand the pitfalls, practice the avoidance techniques and review the quality of your information, you can assure yourself of adequate information.
Optimizing cost/time vs. perfection
Identify all missing data and either obtain it (if possible) or attempt to make reasonable presumptions.
Identify all presumptions and determine appropriateness of making presumptions at these specific places.
Give each presumption a confidence rating and review quarterly.
Eliminate those that are inappropriate or have low confidence ratings.
Identify perceptions and challenge them.
Identify areas where deception is possible. Seek independent confirmation if possible.
Give each assumption a confidence rating and review them quarterly.