Safety Stock Formula

Problem

Compute safety stock as z * sigma_demand * sqrt(lead_time), where z is the service-level multiplier and sigma_demand the demand standard deviation per period.

Return 0.0 for negative lead time.

Hint

Demand variance over the lead time grows linearly, hence the square root.

Test cases

case 1

in: [1.65,10,4]

expected: 33

case 2

in: [2,5,1]

expected: 10

case 3

in: [1.96,0,9]

expected: 0

case 4

in: [1.5,2,0]

expected: 0

Starter codePython

def safety_stock(z, sigma_demand, lead_time):
    # Your code here
    pass

4 test cases · run your code against them in the editor