Many great practitioners across a number of disciplines have professed admiration for a thorough checklist. Some notable investors who are in this camp include Warren Buffett, Charlie Munger, Michael Mauboussin and Mohnish Pabrai. There are many reasons to like a good checklist, for it's a great means through which to impose self-discipline and to leave no rock unturned in your analysis. Humans are constantly exposed to the perils of behavioral biases and checklists are the best method I have encountered to help combat human misjudgment (see some of my lessons learned from the Santa Fe Institute on Risk: the Human Factor).
Some people use checklists with binary (yes/no) questions, while others look for more thought-out analysis for each element. I have combined a little bit of both, with the aim of constructing a coherent and thorough basis for each investment I undertake. One of my goals in posting this checklist here is to elicit feedback from some of you readers out there on other elements that may be helpful, particularly in the qualitative areas.