Julian Dates as Lot Numbers
One technique I've seen was in a shop where they assigned the Julian Date to everything poured in a particular day.
Office Max/Office Depot sell calendars that have the number of the day of the year indicated in the lower corner of either each page or each box (on a monthly calender,) i.e., 1 to 366 (when its a leap year.)
Any day number with less than three digits should be prefixed with Zero(s), i.e., the full Julian Date has been standardized to a four-digit datum.
You just prefix that day number with the last digit of the calendar year to create a Julian Date.
For example, today's Julian Date is 9065 as 6 March 2009 is the sixty-fifth day of the year, hence anything poured/made on this date could have 9065 assigned as the lot number.
For multi-lots produced on the same day you could use 9065-A as the first batch, 9065-B the second, etc. Or, 9065-01 through 9065-99 for when you have a bunch of different lots/batches created on the same day.
What makes this technique nice is if someone later calls and asks when lot number nnnn was poured/made, you can flip to any calendar in the office with the indicators and tell them the date without having to hunt down and fiddle in a paper record.
Also, if later you find out that lot number 9065 had 28% rejection by your customer, you can examine any related production records for that date and/or the employee assigned that day to try to narrow down and correct the cause of the problems.
What ever technique you use, Julian Date or some other, be consistant and keep good records.
You may also be aware that the US Federal government also uses Julian Dates, but their fiscal year starts on 1 October, not 1 January.
Please, do let us know which lot number technique you finally select.
Stan Db