If both the average flow rate and average flow time of a process are increased by 50%, the percentage change in the average number of units in the process is:

(a) 125%

(b) 50%

(c) Cannot be determined

(d) 225%

The percentage change in the average number of units in the process is 125%.

Explanation:

Based on Little's law;

Average inventory = average flow rate * average flow time

Let inventory = I, average flow rate = R and average flow time = T

Thus, I = R*T = RT

Now, Average flow rate and average flow time are increased by 50%

R' = R + 0.5R = 1.5R

T = T + 0.5T = 1.5T

So, inventory, I' = 1.5R*1.5T=2.25RT

Hence, the percentage change in the average number of inventory units in the process.

% change = I' - I = 2.25RT - RT = 1.25RT or 125%

Thus correct answer = 125%