Question

In their Portland, Oregon facility, Wavy Wood Works makes several types of wood bowls from coastal drift wood. To make a bowl, the first step is to clean the drift wood. Each piece of drift wood makes a single bowl. There is one cleaning machine. It takes 38 seconds to load each piece of wood and the machine can hold up to 33 pieces. Once all of the pieces are loaded into the machine, it takes 44 minutes to clean the set (no matter the number of pieces in the set). Once the wood is cleaned, 10 skilled artisans carve the bowls, each one takes on average 93 minutes to produce each bowl. After carving, bowls are finished with a stain. It takes 35 seconds to load each bowl into the stain machine. The staining machine holds up to 33 bowls. Once all of the bowls are loaded, they are soaked for 78 minutes. After staining, bowls are unloaded onto drying racks. There is plenty of space on the drying racks. What is the maximum capacity (bowls per hour) of this process? (Do not round intermediate calculations. Round to 2 decimal places.) bowls per hour Suppose Wavy wants to operate with the same number of bowls in each batch that is cleaned or stained. For example, if they clean in batches of 30, then they stain in batches of 30 as well. What batch size (in bowls) minimizes their inventory while allowing the process to produce at the maximum flow rate? (Use unrounded capacities from Part a. Round to 2 decimal places.) bowls per batch

Answer 1

a.

	Cleaning	Carving	Staining
Capacity	33	10	33
Time	44+38/60*33	93	78+35/60*33
Time	64.9	93	97.25
Bowls/Min	0.508474576	0.107527	0.33933162

Capacity of process is the slowest step = 0.107527 Bowls/min = 6.45 Bowls/hr

b. Batch size = Bottleneck capacity x Set up time /(1- (bottleneck capacity x processing time))

Batch size for cleaning = 0.107527 x 44 / (1- (0.107525 x 38 /60)) = 5.08

Batch size for staining = 0.107527 x 78 / (1- (0.107527 x 35/60) = 8.95

We would use the higher batch size as the lesser batch size would lower the capacity

Thus, answer =8.95