Replenishment Signals

A replenishment signal communicates the need to replenish inventory in a Kanban circuit. 

Signal Types

There are three types of replenishment signals:

Visual: Replenishment is signaled manually, e.g., by attaching a printed Kanban card to the part or returning an empty container to the replenishment source. Electronic replenishment is not allowed.

Electronic: The user initiates the replenishment signal either by using Kanban Replenishment Request or by scanning the cards with a bar code reader. The system electronically processes the request and generates the signal. The quantity triggered by the signal is the quantity of one Kanban container.

Automatic (Reorder Point): The system triggers replenishment automatically when the inventory falls to a specified level. This signal type is not a traditional Kanban technique. The signal can be initiated by a dialog box or run as a scheduled job by Kanban Reorder Point Request. Once the signal request is initiated, the system checks the circuit to determine whether a replenishment signal should be created. The system generates the signal when the quantity on hand plus the quantity of the work in process (WIP) within the lead time falls below the reorder point quantity. The quantity triggered by the replenishment signal depends on whether a lot size is defined, assuming the formula type is Constant. If a lot size is defined for the circuit, then the quantity triggered will be the lot size quantity rounded up to the nearest Kanban container quantity. If a lot size is not defined for the circuit, then the quantity triggered will be the quantity required to fill the empty Kanban containers, rounded up to the nearest Kanban container quantity.

What the Signal Generates

Electronic signals can trigger a variety of actions, depending on the type of Kanban circuit and the inventory part's setup attributes, as shown in the following table.

Automatic (Reorder Point) Example

This example assumes a Kanban circuit with the following characteristics (see Fig. 1):

Number of Kanbans:  3
Quantity per Kanban: 4
Reorder Point Quantity: 10
Lot/Transfer Quantity: 0

Fig. 1: Beginning Kanban Circuit

Step 1:

Starting with full Kanbans with a total of twelve units, assume two units are consumed, leaving a quantity of ten (see Fig. 2). If the system is scheduled to request replenishment at this time, it will see that the total quantity on hand is not below the reorder point of ten, so no replenishment request is issued.

Fig 2: Kanban Circuit, Step 1

Step 2: 

Another unit is consumed, leaving a total quantity of nine (see Fig. 3). If the system is scheduled to request replenishment at this time, it will see that total quantity on hand is below the reorder point of ten, so a replenishment request is issued. The quantity triggered must be in increments of full Kanbans, so a quantity of four is requested. 

Note: If a lot/transfer quantity were defined, then the quantity triggered for replenishment would be the lot size rounded up to the nearest full Kanban.

Fig. 3: Kanban Circuit, Step 2

Step 3:

One more unit is consumed, leaving a total quantity of eight (see Fig. 4). If the system is scheduled to request replenishment at this time, it will see that total quantity on hand is below the reorder point of ten. However, the system also is aware of the replenishment request issued in step 2. Since the quantity already triggered is one full Kanban (four units), the total quantity will be twelve once this quantity is received. Assuming that the replenishment will be received within the lead time for the part, the total quantity on hand will be greater than the reorder point of ten, so a replenishment request is not issued at this time.

Fig. 4, Kanban Circuit, Step 3