Xerox 6180N Generic MICR Fundamentals Guide  - Page 120

Problem solving A statistically significant test to detect a 0.5 per cent rejection rate can be achieved with 2,000 to 3,000 documents. (The test case should not be less than 200 documents.) If the test set is too small, it may be biased by the fact that reader sorter performance is poorer when the machine is starting up than when it has been operating steadily for some time. • Are there characters that appear more often as the reason for rejection? Although a reject rate based on character failure is not generally significant, a specific character may be causing the problem. Check to see if a certain character is driving the reject rate, and if failure occurs when the character is in a particular position in the document. • Are the rejects clustered by field? If multiple rejects occur in a particular field, a mechanical problem may exist in the printer or the reader sorter. • Is there a pattern to where the rejects occur? Rejects can appear in the document consecutively, in groups, or randomly. Look for a pattern; for example, the same character, the same field, or appearance after every certain number of sheets. • How do the rejects compare with accepted documents? Check to see if the rejects have been improperly cut, or if any other difference is obvious. • Are all documents accounted for? At the end of a run, the number of accepts plus the number of rejects should equal the total number of documents submitted. • What is the sorter type and location? If there are problems, it may be useful to know what type of sorter was used. If possible, obtain the following information for reference and machine identification purposes: sorter type, model number, user ID, and serial number. 7-8 Generic MICR Fundamentals Guide