When the process distribution is ready to be assessed, the assessor fills out the check sheet's heading. For each combination of suspected causes, the assessor actively observes the process. Each time the process generates an output, he or she assesses the output for defects using the agreed-upon methods, determines the category in which the defect falls, and adds the symbol corresponding to that defect category to the cell in the grid corresponding to the combination of suspected causes. If no defects are found for a process output, no symbol is entered.