Calculating the number of kanban card sets:
A hospital desires to set up a Kanban system to manage its supply of blood with the regional blood bank. The regional blood bank transport blood to the hospital each of the day with a half day order lead time (that means an order place at 4 PM today shall be delivered at 4 AM the following morning). Internally, the hospital purchasing group places orders for blood each of the day at 3 PM. Blood is measured by the pint and is shipped in containers that contain six pints. For a specific blood type, the hospital uses an average of 12 pints per day. Because of the critical nature of the blood shortage, the hospital desired to carry a safety stock of two days' expected supply. How many Kanban card sets must the hospital prepare?
This problem is a typical problem depicting the use of Kanban in real environment. By using the data given, the variables for this problem are as follows:
D = 12 pints per day
L = 1/2 day (lead time)
S = 200 percent (safety stock, as a fraction this is 2.0) C = 6 pints (container size)
k = (DL (1 + S ))/ C = (12 × 0.5 × (1 + 2)) /6= 3
This indicates that we ought to prepare three kanban card sets. Each time a new container of blood (containing three pints) is opened, the card shall be sent to purchasing and another three pints of blood shall be ordered. While the blood is received the card shall be attached to the new container and moved to the blood storage area.