Skycell a Major european cell phone manufacturer is making p

Skycell, a Major european cell phone manufacturer, is making production plans for the coming year. Skycell has

worked with its customers (the service providers) to come up with forecasts of

monthly requirements (in thousands of phones) as shown in the Table below, such

as demand in Jan. is 1,000,000 units

Table: Monthly Demand for Cell Phones in Thousands

Month Demand

January 1,000

February 1,100

March 1,000

April 1,200

May 1,500

June 1,600

July 1,600

August 900

September 1,100

October 800

November 1,400

December 1,700

Manufacturing is primarily an assembly operation, and capacity is governed by

the number of people on the production line. The plant operates for 20 days a

month, eight hours each day. One person can assemble a phone every 10

minutes. Workers are paid 20 euros per hour and a 50 percent premium for

overtime. The plant currently employs 1,250 workers. Component costs for each

cell phone total 20 euros. Given the rapid decline in component and

finished-product prices, carrying inventory from one month to the next incurs a

cost of 3 euros per phone per month. Skycell currently has a no-layoff policy in

place. Overtime is limited to a maximum of 20 hours per month per employee.

Assume that Skycell has a starting inventory of 50,000 units and wants to end

the year with the same level of inventory. Assuming no backlogs, no

subcontracting, and no new hires.

Please construct an aggregate planning model. (Constructing an aggregate planning

model means defining the decision variables and writing out the objective function

and the constraints for the AP optimization problem.)

Hint:

• You might want to use SOME of the following decision/planning variables

for this problem:

Ht = # of workers hired in month t (t = 1,..,12)

Lt = # of workers laid-off in month t (t = 1,..,12)

Wt = # of workers employed in month t (t = 1,..,12)

2

Ot = # of hours of overtime in month t (t = 1,..,12)

It = # of units (000s) held in inventory at the end of month t (t = 1,..,12)

Ct = # of units (000s) subcontracted in month t (t = 1,..,12)

Pt = # of units (000s) produced in month t (t = 1,..,12)

Solution

Ans-

Weekly demands at Hot Pizza are as follows: Week Demand Week Demand Week Demand 1 108 5 96 9 112 2 116 6 119 10 102 3 118 7 96 11 92 4 124 8 102 12 91 Estimate demand for the next four weeks using a four-week moving average as well as simple exponential smoothing with = 0.1. Evaluate the MAD, MAPE, MSE, bias and TS in each case. Based on MAD, which of the two methods do you prefer? Why? 4. (Chapter 3) Skycell, a major European cell phone manufacturer, is making production plans for the coming year. Skycell has worked with its customers (the service providers) to come up with forecasts of monthly requirements (in thousands of phones) as shown in the Table below, such as demand in Jan. is 1,000,000 units. Table: Monthly Demand for Cell Phones in Thousands • Manufacturing is primarily an assembly operation, and capacity is governed by the number of people on the production line. The plant operates for 20 days a month, eight hours each day. One person can assemble a phone every 10 minutes. Workers are paid 20 euros per hour and a 50 percent premium for overtime. The plant currently employs 1,250 workers. Component costs for each cell phone total 20 euro