A shoe assembly plant buys leather tops and soles from its suppliers. The leather tops have no color on them when bought. The assembly plant first dyes the leather with colors like black, beige, brown and cream. Then it sews the colored leather tops to the soles. A shoe consists of one leather top and a sole. Basically there are two operations in the shoe plant: Coloring and Sewing. The activity times and set up times for these operations are given in minutes as follows:
Coloring: = Setup time 80 minutes & Per-unit processing time 2 minutes/shoe
Sewing: = Set up time 0 minutes & Per- unit processing time 3 minutes/shoe
Leather tops are processed in batches in the coloring stage with setup time of 80 minutes and per-unit processing time of 2 minutes/shoe. Sewing stage does not need any setup time, and the per-unit processing time is 3 minutes/shoe.
1. What is the capacity of the coloring stage (in [shoes/hour]) when the batch size is 40?
2. What is the capacity of the sewing stage in [shoes/hour]?
3. Assume that the demand of the process is 30 [shoes/hour]. What is the optimal batch size (in number of shoes)?
4. Assume that the demand of the process is 10 [shoes/hour]. What is the optimal batch size (in number of shoes)?