In my previous posting on inventory accuracy in the warehouse, I referred to locator check digit feature in R12. In this blog entry I want to provide more details about this small but powerful feature to improve inventory accuracy in the warehouse. The biggest benefit of locator check digit is that it ensures that warehouse operator physically travels to the locator and performs transaction. Consider this example:
Suppose you have a "Pick to Clean" picking strategy and WMS directs the warehouse operator to pick the material from a far out locator say X9-2-4. What if the warehouse operator notices the very same product at locator Y4-5-2? What if the operator physically picks the material from Y4-5-2 but confirms the pick transaction at X9-2-4? No exception is logged and now you have two locators X9-2-4 and Y4-5-2 with incorrect inventory. What happens when WMS suggests X9-2-4 for putaway since it shows up as an empty locator? What does the putaway operator do when he travels to X9-2-4 and finds it occupied? Does he find another empty locator and confirms put away at X9-2-4?
Sounds familiar? How does check digits help? The way check digits work is that each locator is associated with a check digit and transactions can be confirmed only using check digit. This check digit is printed on the locator label physically but it is not suggested to the operator on the mobile device. Meaning that operator can use the locator suggested on the mobile device to travel to the locator but must go to the locator to record its check digit. Besides check digits also helps in faster data entry especially if you have to enter long locator values manually.
Here is a small utility that I have developed in Excel that could be useful for initial locator or warehouse bin definition in your warehouse. To summarize the Excel file does the following:
Auto generates locators using range for 3 segments such as Row, Rack and Bin or X, Y and Z coordinates.
Generate check digits for each locator using algorithms such as Modulo-10, Alphanumeric, or Unique 4 digit check digit
Create locator labels with check digit. You need to have an XML enabled printer such as Zebra 110XiIII, Intermec PM4i, Sato CL412e, Toshiba B-SX6T, Cognitive Advantage LX, Datamax I-4308 or Printronix T5206. Alternatively you need an XML enabled print server such as Loftware, Niceware, Optio or Unibar.
The excel sheet can run a macro to generate the label XML. If you wish to randomize the check digits, there is a macro for it as well.
The locator generation parameters includes a range for each segment. Each segment in turn is split into two sections and you could provide a range for each section using the "From" and "To" parameter. You could for example create locators from EA1-A1-A11 to EA2-D3-Z14 by entering the "From" and "To" parameters as follows:
The Excel sheet will create locators for all permutations of "from" and "to" segment range values e.g. A1, A2, A3, B1, B2, B3, ...etc. Once again the excel sheet can be downloaded here:
http://blogs.oracle.com/adityaAgarkar/gems/locator.zip
Please note that this is freeware and you are free to modify or update it as you please.
Comments (2)
The concept of the locator check digit is an excellent idea as it requires warehouse personnel to go to the location that is intended. Any process that prevents humans taking shortcuts around standard operating procedures will help inventory accuracy immensely.
Posted by Scott Peterson | May 25, 2007 2:50 PM
Posted on May 25, 2007 14:50
Wow - nice Excel sheet showing how permutations can be generated automatically. I was looking for something like that!
Thanks!
Posted by Sid B | March 18, 2009 1:29 AM
Posted on March 18, 2009 01:29