Sandy is asked to produce 250 squidgets an hour. It takes 30 minutes to receive the necessary materials from the previous workstation. Each output container holds 25 squidgets. The factory currently works with a safety factor of 10%. How many kanbans should be circulated between Sandy's process and the previous operations?

Kanban is a method that is used to mange workflow in order to assist in visualizing the work and maximize the efficiency of a workers as well as making the workers agile.

The formula for calculating the number of Kanban is given as follows:

Number of Kanban = (Dd × LT × (1 + SS)) ÷ QC .................. (1)

DD = Daily required production level = 250

LT = Lead Time (in minutes) = 30

SS = Safety Stock = 20% = 0.2

QC = Number of squidgets in a container = 25

Substituting the values above into equation (1), we have:

Number of Kanban = (250 × 30 × (1 + 0.2)) ÷ 25

= (250 × 30 × 1.2) ÷ 25

= 9,000 ÷ 25

= 360

Therefore, the number of kanbans to be circulated between Sandy's process and the previous operations is 360.