The intent of the MII process is to utilize measurement-based estimates to improve the inventory process for a specic facility (or small group of facilities) over results using traditional inventory methods. If successful, the improved inventory process would then be used to accurately estimate emissions for each of the facilities' operating states, over extended periods the result needed for regulatory reporting, voluntary initiatives, and similar purposes. The question then, is how do TD measurements inform inventories? In this study, the TD/BU disagreement could originate from three potential causes (or any combination of the three):