Using the following weekly demand data for a new soft drink, determine the upper and lower control limites that can be used in recognizing a change in demand patterns. Use _+3 control limits.
Week 1 - 3500
Week 2 - 4100
Week 3 - 3750
Week 4 - 4300
Week 5 - 4000
Week 6 - 3650
process Mean= Sum all the demands of week /number of week =23300/6 =3883.3
Demand | |
Week 1 | 3500.0 |
Week 2 | 4100.0 |
Week 3 | 3750.0 |
Week 4 | 4300.0 |
Week 5 | 4000.0 |
Week 6 | 3650.0 |
Average | 3883.3 |
Find variance of demand = sum of ( Average-Demand of week)2 / 6
Std. deviation of demand = sqrt( Variance )
Demand | Variance | |
Week 1 | 3500.0 | 146944.4 |
Week 2 | 4100.0 | 46944.4 |
Week 3 | 3750.0 | 17777.8 |
Week 4 | 4300.0 | 173611.1 |
Week 5 | 4000.0 | 13611.1 |
Week 6 | 3650.0 | 54444.4 |
Average | 3883.3 | 75555.6 |
Std. Dev | 274.9 |
UCL = Process Mean + 3* Std. dev
LCL = Process Mean - 3* Std. dev
UCL = 3883.3 +3*274.9 = 4708
LCL = 3883.3 - 3*274.9 = 3058.6
Get Answers For Free
Most questions answered within 1 hours.