Kanban Calculations

Kanban is a pull-based inventory management system that helps control production and inventory levels. These calculations help determine the optimal number of Kanban containers and average inventory levels needed to maintain efficient production flow.

#Average Period Demand

The average demand per period (shift) based on the value stream production requirements.

#Replenishment Time

Time required to replenish a Kanban container, calculated using cycle time and shift duration.

where Effective Cycle Time is determined by:

• If OEE is available: Use Actual Cycle Time
• Otherwise: Use Designed Cycle Time

#Kanban Quantity

Number of Kanban containers needed to maintain production flow, accounting for demand, replenishment time, and safety factor.

#Average Inventory

Average inventory level maintained in the Kanban system.

#Example

Consider a process with the following parameters:

• Units Per Week: 1000
• Operating Days Per Week: 5
• Shifts Per Day: 2
• Container Size: 25
• Safety Factor: 1.2
• Effective Cycle Time: 30000 seconds (8.33 hours)
• Shift Duration: 25200 seconds (7 hours)

1. Average Period Demand: $\frac{1000_{\text{units/week}}}{5_{\text{days}} \times 2_{\text{shifts}}} = 100_{\text{units/shift}}$

2. Replenishment Time: $\frac{30000_{\text{seconds}}}{25200_{\text{seconds/unit}} \times 2_{\text{shifts}}} = 0.595_{\text{units/shift}}$

3. Kanban Quantity: $\frac{100_{\text{units/shift}} \times 0.595_{\text{units/shift}} \times 1.2}{25_{\text{units/container}}} = 2.856_{\text{containers}}$

4. Average Inventory: $0.5 \times 25_{\text{units/container}} \times 2.856_{\text{containers}} = 35.7_{\text{units}}$