Since all serialized valves have to pass through one of three test stands, it was decided that this was the point at which we would capture all information about the valve. Serial number, test results, and inventory movement would all take place using terminals installed next to each test stand. We also needed to account for a gate valve option that could be added to all tested valves after testing. The gate valve option changes the part number of the unit.
Since we need to get additional data from the user, we felt we may as well report completions as they occurred. This required some changes from the batch kanban cards, which only recorded completions when the entire work order was completed. We also needed to account for the gate valve option that can be added to all our serialized valves. Because of the great variety of serialized valves, all made of common subcomponents, we needed to ensure that the test stand operator was reporting on exactly the right part number.
We made a slight modification to the kanban work order creation program that we used in the batch process. If the kanban card was for a serialized valve (we use product line to identify them), we would print an information label for each valve to be produced. This information label contains the proper part number and description, as well as kanban card information and audit information on the valve.
The information labels are attached to the valve as part of the production process. The test stand operator then uses the data on the label, along with the test stand results and serial number, to let the ERP system know that the correct valve was produced and passed all required
tests. The system then backflushes the inventory. When all information labels have been used, the system will automatically close the work order.
When the ERP system records a successful test stand entry, it produces a bar-coded label that will be used in the shipping process. It also logs the test information and serial number in the database. The information label is removed and replaced by the bar-coded label. The information label is saved for later audit.
A similar process is used if the valve needs to be gated. The information required by the ERP relates only to the type of gates being added. It also validates that the valve has been tested. At this point the test data and serial number are reentered into the database with a new part number. All of this must occur properly because the shipping process will again validate against this database.
CLOSING THE CIRCLE
Our production process has produced and accurately reports finished goods to inventory. This does us not good at all if we can't ensure that our shipping process can ship the right parts to the right customer, when it was promised. It is time to close the circle. This is also the point where we found we had to spend a little money to do the job right.
We had an advantage in developing this process because most of the parts we ship are serialized. This gives us a unique, easy-to-identify part that can be crosschecked during shipping. We do, however, need to identify and verify parts that do not have a serial number. Usually, it is not desirable to have a work center doing a particular task two different ways. This was unavoidable in shipping if we wanted to verify our shipments. With serialized products, we not only wanted to record the part number, but the serial number as well. This requires identifying these parts one at a time to the ERP system. In the case of non-serialized valves, we can verify the part number, but since that is the only unique identifier, we do not necessarily need to record them one at a time.
The biggest task was to figure out the best way to record the shipping transactions. Being rather averse to spending a lot of money, we tried to use what we had on hand, dumb terminals. After that didn't work out, we tried a variety of inexpensive, hand-held devices, either on a wire or storing and transferring from a memory device. All these methods were failures. We finally took the plunge and moved to radio frequenq' (RF) handheld devices. We have actually done this twice because our parent company insisted that we change our ERP system after we had implemented an RF solution.
When an order needs to be shipped, the packer uses the RF device to find the order in the ERP database. The item's part number is bar-code scanned and verified that it is indeed for that order and that the item has been allocated. This becomes important later in the process if the part is not serialized. The program then determines if the valve is serialized based on product line. If it is, the packer scans die serial number, which is located on the same label as the part number. The ERP system checks that a part with that part number and serial was indeed produced, and that it has not been used already. If these tests are passed, the item is automatically updated for one unit. The packer would then repeat the process for the next serialized unit.
If, after the part number is scanned, the system determines that the unit is not a serialized unit, stock status is checked. There must be enough units allocated to satisfy the order, or the system warns the packer not to continue picking this line. If there are enough units allocated, the packer verifies that he has picked the required number of units.
WHAT THE FUTURE HOLDS
As the world around us changes, we too must change. This project is not complete. Upper management has already ready identified three areas that the action teams needs to continue to work on:
• Data collection for serialized valves will need to be
modified to work more effectively with a new high
speed assembly line.
• Kanban card control need to be tied directly to our
ERP system's forecasting module.
• This process, with necessary local modifications, needs
to be tried at other corporate manufacturing sites.
While inventory accuracy throughout any system is important, the action team decided that if we could tightly control what went into the production process (purchase order receipts) and what came out of the production process (shipment processing), the middle would take care of itself. Because our materials are both too large and heavy or of no value except for use in our production process, we don't worry about theft. Therefore, what happens inside the plant walls should be traceable to production. This is a purely financial measure and was used to justify the any cost associated with the project.