problem 1)a)
Develop the aggregate plan for the given data using Trial and error Method, Initial Inventory is nil and a final inventory of 200 units is required.
Period Demand (units) Maximum capacity (units)
Quarter Regular time Overtime Sub-contracting
1 1200 1800 400 300
2 2100 1800 500 300
3 3200 1800 600 300
4 2100 1800 400 300
Costs: Regular time production = Rs 50 / unit, Overtime Production = Rs65/unit, Subcontracting = Rs 80 /unit and inventory carrying = Rs 5 /unit/quarter
b) A production planner must decide the sequence in which to process the 6 customer orders on a single manufacturing facility. The processing time in days and their due dates are given below.
Schedule the jobs using FCFS, SPT, EDD and Critical Ratio sequencing rules and determine Mean flow time, Average job lateness and Average number of jobs in the system.
Job ( in order of arrival) Processing time (days) Due date (days hence)
A 2 4
B 5 18
C 3 8
D 4 4
E 6 20
F 4 24
problem 2)a) The demand for a chemical is at a constant rate of 100000 kg per year. The cost of ordering is Rs.500. the cost per kg of the chemical is Rs 2. The shortage cost is Rs 5 per kg / year if the chemical is not available for use. Determine the optimal order quantity? The inventory carrying is Rs 30.
b) The rate of demand for an item is 60 unit per week and the normal lead time is 3 weeks. find out the safety stock and ROP in the following cases.
i) If safety stock is assumed to be 25% of Lead time consumption.
ii) If safety stock is assumed to be 2 weeks requirement.
iii) If the maximum lead time basis is to be used and the maximum lead time in the past has been 6 weeks.
v) describe in brief MRP System Inputs and Out puts.