000 sloos Sample size n 2 3 4 5 6 7 8 9 11 10 12 13 Mean Factor A2 1.880 1.020 0.729 0.577 0.483 0.419 0.373 0.337 0.308 0.285 0.266 0.249 Lower limit D3 0 0 0 0 0 0.076 0.136 0.184 0.223 0.256 0.283 0.307 Question 2: Tom is a New York manufacturer that produces sewing machines. The workshop current has 16 workers, and each worker produces 15 sewing machines per month. The operations manager is about to prepare an aggregate production plan that will cover the next six months. The initial inventory is 100 sewing machines. The demand for each month is given in the following table. The cost and production information are as follows: Month Demand 1 2 3 4 5 6 300 200 400 600 300 400 Cost Data: Regular-time labour cost $12 per sewing-machine Overtime labour cost $20 per sewing-machine Subcontracting cost $25 per sewing-machine Holding cost $1 per sewing-machine per month Hiring cost $50 per worker Firing cost $40 per worker Production: Max. overtime output 50 sewing-machines per month The manager would like to keep the initial workforce level and not use hiring/firing. The plan can use overtime and subcontract options. The manager also would like to use the initial inventory as early as possible, no shortages each month, inventory at the lowest level for each month and no inventory in the end of month 6 in this plan. Develop an aggregate plan. What is the total cost of this plan? (20 marks). Question 3: The table below contains information about five jobs waiting to be processed at work station 1. Job A B C D E Processing Time (Hrs.) 14 10 18 2 4 Hours Until Due 15 20 18 16 21 a) Based on average flow time, which rule is better: EDD vs MST? (10 marks). b) Based on the average WIP, which rule is better: EDD vs MST? (10 marks). 3