Om Assignment #3

7.13 Question #2

a)

Derive the process cycle time of the work cell by adding the individual process times in the various stations

@ station 1, the process time is 20minutes/unit in both the parallel machines A&B

@ Station 2, time is 12 minutes/unit in the 2 parallel machines

@ station 3, the process time is 8minutes/unit

There for the total process cycle time is 20minutes+12+8=40minutes.

b) Compute the system process time by working out the bottleneck capacity.

@ station 1, there are 2 parallel machines, eac w/ with 20minutes per unit process time. 2 machines together are able to deliver 1 unit in 10 minutes.

@ station 2, there are 2 parallel machines, each having a processing time of 12 munutes/unit. The 2 machines together are able to deliver 1 unit in 6minutes.

@ station 3, the processing time is 8minutes/unit.

Comparing the three stations, station 1 is the slowest as it takes 10minutes per unit. Station 1 is the bottleneck station.

Therefore, the system process time is 10minutes.

c) Calculate the weekly capacity of the work cell, given that the firm operates 8hrs/day, 6 days a week and that the system process time is 10minutes as follows:

Weekly capacity = 8hrs/day*60mins/hr*6daysAweek÷10mins/unit

=2880/10 units/week

=288 units/week

The weekly capacity of the work cell is 288 units a week.

d)

The addition of the second machine @ station 2 moved the bottleneck to station 1.

The process time changed from 12 to 10minutes.

The weekly capacity increased from 240 units a week to 288 units a week. The addition of the 2nd machine @ station 2 increased the capacity by (288-240) units a week i.e 48 units a week.

Question #3 7.25

1. BEP-xman for the manual process, given that the fixed cost F=$37500, the unit selling price S=$2.50 per bag and the unit variable cost V=$1.75 per bag by using the formula:

BEP-xman = F÷S-V

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