Question

Kanban and takt time

A work center uses kanban containers that hold 300 parts. To produce enough parts to fill the container, 90 minutes of setup plus run time are needed. Moving the container to the next work station, waiting time, processing time at the next work station, and return of the empty container takes 140 minutes. There is an overall demand rate of nine units per minute.

a. Calculate the number of containers needed for the system.

T is the time required for a container to complete the entire circuit. In this example, it is 90 minutes for setup and run time plus 140 minutes to move the container through the rest of the circuit.

N = DT / C = (____ x (____ + _____)) / _____ = _____ à round up to ______

b. What is the maximum inventory in the system?

Since production will stop when all containers are full, the maximum inventory is when all containers are full. That can be expressed as n x C.

n x C = _____ x ______= ________

c. A quality team has discovered how to reduce the setup time by 65 minutes. If these changes are made, can the number of containers be reduced?

n = DT / C = (_____ x (____ + _____)) / ______ = _______ à round up to ______

Yes or No?

d. What is the takt time for this process?

Takt time = 1 minute / 9 units = _____ units/minute or 60 seconds / 9 units = _______ units / second.

Answer 1

a. Calculate the number of containers needed for the system.

T is the time required for a container to complete the entire circuit. In this example, it is 90 minutes for setup and run time plus 140 minutes to move the container through the rest of the circuit.

N = DT / C = (9 x (90+ 140)) / 300= 6.9à round up to 7 (9 units/minute demand to be full fill for 90+140min waiting time and contaner capacity 300 pcs)

b. What is the maximum inventory in the system?

Since production will stop when all containers are full, the maximum inventory is when all containers are full. That can be expressed as n x C.

n x C = 7 x 300= 2100 (7 container with 300 capacity)

c. A quality team has discovered how to reduce the setup time by 65 minutes. If these changes are made, can the number of containers be reduced?

n = DT / C = (9x (65+ 140)) / 300 = 6.15 à round up to 7 (here round up will be at higher integer beacuse once 6th contaner is full there will be need of one container to store the goods. so answer is no, number of container will not be reduce.

Yes or No?

d. What is the takt time for this process?

Takt time = 1 minute / 9 units = 9 units/minute or 60 seconds / 9 units = 0.15 units / second.(9/60=0.15 units/second)

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