Four Steps to Pain Free Lot Traceability in Manufacturing
Posted by Randy Flamm on Fri, Apr 16, 2010 @ 07:24 AM
We've all read how a popular automaker has been under fire recently for their quality problems. I can just imagine how devastating it must be to find out that a product you've been shipping for years is subject to a recall for a quality defect. The first step in damage control would be to completely understand the underlying cause of the problem. Many times the fault lies in one of the raw materials used to manufacture the product. In that case, strong lot tracing functionality can be the difference between recalling millions vs. recalling thousands or less. In order for lot traceability to be cost effective it should be built into the normal workflow of the manufacturing process.
The first step begins when the raw materials are purchased and received. At that time the vendor lot number of the container of material is communicated to your ERP system. This communication can take many forms such as a vendor supplied advance shipping notice (EDI ASN), bar coded labels or packing slips. However it's done the lot number must follow the raw material until it is consumed by the next level product. Many times an agreement can be made with the vendor to supply customer defined labeling for serialized control that can be sent electronically via EDI to the ERP system. This method eliminates the cost and accuracy issues of relabeling while converting foreign vendor labels to ERP native serialized labels. Business rules for manual receipts include being able to setup mandatory lot number entry before the transaction is allowed to go through.
The second step is to rely on the inventory control system to keep the material container lot numbers separated from each other. This separation must be built into the system and cause minimal burden to the user. As an example, a warehouse inventory location can contain many lots of the same material but they all need to be listed by FIFO and accessible for allocation or back flushing individually.
The third step is to have the system generate and assign a manufacturing (FG) lot number to the products being produced in real time. All levels of products including sub assemblies will be assigned FG lot numbers during production. Typically the generation of a new FG lot number happens when an event takes place. Events are things like starting a new raw material lot number, machine restarts or even operator changes. As a rule, the more often FG lot numbers are changed the more granular the lot traceability will be making it easier to pinpoint critical information.
The fourth step occurs during production reporting via hand scanners, touch screens, automated conveyors, pallet wrappers or input screens. The result of the reporting is a "balanced" inventory transaction. A balanced transaction includes adding the parts that were manufactured and relieving the raw material used to make them. As the transactions are applied to the perpetual inventory they are logged in the transaction log. All inventory transactions are logged. No exception. The transaction log is the key to lot number traceability. It contains all kinds of information about the transactions including both FG lot number and raw material lot number fields. This creates the ability to query the transaction log to cross reference lot number "trees".
Incorporating these 4 steps during the normal production reporting and inventory transaction process will provide bullet proof pain free lot traceability.
To download product datasheets on various capabilities mentioned, click here.