Since I got a request for more posts about Service management, I thought I’d dig into my bag of tricks. One of the things I’ve run into a lot of issues is serialization. For some reason, serial numbers seems to hold a special place of confusion for many customer. Today I want to talk about the serial number number scheme. I’ve picked this as my starting point for serialization because many of my recent projects have had a lot of trouble coming to decisions on this topic.
Serial numbers have a great starting point when it comes to numbering. As of ERP 5.0 or 6.0 (not sure exactly when), SAP added a field called SerializLevel.
This field allows you to make the serial number number scheme unique at a global level or unique at a material level. This subtle difference has huge implications on the number scheme. If SerializLevel is blank, then serial number is only unique at a material master level. To put things simply, the combination of serial number and material number is unique, but the same serial number can show up for any material number. If SerializLevel is set to 1, then the serial number is unique across the SAP instance. This means that no serial number will ever show up for any other material. SAP accomplishes this by linking the serial number to the equipment record number. I’ll have a future post that goes into the details of serial numbers vs. equipment records. Since every business is different, and you can often become locked into a particular numbering scheme. The number one decision to make is if the serial number is unique across the organization, or if it can be reused for materials.
There are some things to beware of when using this functionality. The SerializLevel field is plant dependent. This means that you do have the ability to set this value differently across different plants. I discourage setting this differently for the same material. If you were to set the value to be unique across the origanization in one plant, but unique by material in another, you’ll see some very inconsistent results in the history. I’ll go into the serial number history in a future post, but when it comes to serialization, consistency is key.
The final issue to cover when it comes to serial numbers is what I’ve heard called “intelligent” serial numbers. When I say intelligent serial numbers, I use the term loosely. This can be anything from adding a prefix by product to each number, adding in a manufacture date, or it could be a combination of alphanumeric characteristic that have a decoder ring to explain them. In my humble opinion, this is a very slippery slope and should be avoided at all costs. When you move down the path of “intelligent” number schemes, you must introduce ABAP code to accomplish this. I believe the user exit is IEQM0003 (don’t remember for sure if this is the correct exit). Regardless, if you start creating an “intelligent” number scheme, you must have multiple number ranges available, you need code to possibly shift from one range to the next. For anyone that’s been doing SAP for a while, you know that every time you introduce code, you introduce risk, and you introduce additional time to implement.
The most important question to ask is “Why do you need an “intelligent” serial number?” A serial number should be nothing more than a tracking mechanism for a product. Requiring the serial number to mean something is a not something that add value to a product, but it does increase the cost. Anyway, I’ll get off my soap box now. You get the idea that I think intelligent number schemes are costly, risky and unnecessary.
I hope you found this useful. I hope to hear your comments, thoughts, or let me know things I missed.
Thanks for reading,
Mike